The Current State of Territorial Development of ASEAN Countries and Strategic Types for Balanced Development

Abstract

ASEAN countries are promoting regionally balanced development in their policy in response to development disparity resulting from rapid urbanization. This study aims to draw strategic approaches for balanced development based on the current status of territorial development of the ASEAN countries. Through the lens of Korea’s territorial development experience, this study presents three strategic types for balanced territorial development and an analysis framework to connect the strategic types and the territorial conditions of ASEAN countries. This study analyzes the current status from five aspects: (1) the current status of urbanization and industrialization, (2) the size distribution of cities, (3) the spatial structure of the territories, (4) the state of regional development, and (5) balanced development visions and territorial policies. Based on the analysis results, this study categorizes the ASEAN countries that exhibit similar territorial development and applies the strategic types. This study derives policy measures suitable to each strategic type that will help the ASEAN countries to facilitate balanced development in accordance with their territorial state.

1. Introduction

In 2018, the Association of Southeast Asian Nations (ASEAN) established the Sustainable Urbanization Strategy (ASUS) in response to rapid urbanization. Announcing its support strategies for urbanization, ASEAN countries have cited various problems, such as unequal economic growth and urban expansion in ASUS. ASEAN projects that around 7 million people in the region will move to urban areas by 2025 and, in particular, there will be a surge in mid-sized cities with populations between 0.5 to 5 million by the growing formation of economic clusters and an increase in the number of mega-city satellite cities [1]. It is also emphasized that failing to make efficient use of national territory in response to such rapid urbanization will give rise to external diseconomy, including welfare loss due to overpopulation, deterioration in living conditions, and wider regional gaps, as well as stunted economic growth and sustainable development. For example, research by ASEAN (2022) [2] indicates that poorly managed rapid urbanization forms significant urban poverty and inequality and leads to the fluctuating Gini index of ASEAN regions.

ASEAN emphasizes that urbanization triggered by economic growth “brings disadvantages, including unequal development, the social conflict between communities,” etc., as well as “positive impacts, including as job opportunities, infrastructure improvement, and improvement in people’s living standards” [2] (p.18). Despite the development disparity among ASEAN countries, regionally balanced urbanization and reducing territorial inequalities (hereafter referred to as balanced territorial development) are key issues [3], drawing attention to related policies [4]. Each ASEAN country promotes regionally balanced development in its development policy, with inclusion and fairness at the heart of national spatial planning (see Section 4.5). Some shared strategies of ASEAN countries for territorial development include: building industrial complexes, designating special economic zones, improving transport infrastructure, and promoting urban and regional systems, as well as revitalizing rural areas and linking urban and rural areas.

However, discrepancies in territorial development among ASEAN countries in terms of the level of urbanization, industrialization, geographical concentration, and regional disparity make it difficult to apply a uniform projection to each of the ASEAN countries. As such, an analysis of the current status and characteristics of territory for the ASEAN countries is needed. The analysis can enable ASEAN countries to approach territorial development strategically by deepening the understanding of their territory.

To establish a strategy for the balanced development of ASEAN countries, it is essential to discover and adopt policy measures suitable for each country’s current status and context of territorial development. However, despite the high interest and importance of balanced territorial development, policy measures for it have not been studied much. Previous studies on balanced territorial development can be broadly classified into two types. First, there is research that conceptualizes balanced development and connects it with spatial planning. These kinds of studies were first and mostly conducted in Europe. In the European Spatial Development Perspective published in 1999, the European Commission mentioned that “reconciling the social and economic claims for spatial development with the area’s ecological and cultural functions contributes to balanced spatial development” [5] (p. 10). The document specified the territory of the EU as a new dimension of policy and balanced development as the ultimate goal of European spatial policy. Since then, there have been studies that have attempted to advance the concept [6,7]. For example, balanced development could be connected with “a plurality of choices for populations and firms” within a networked polycentric system [6] (p.233). In addition, in this context, some studies analyzed specific aspects of individual European countries from the perspective of balanced development (e.g., Finka [8] 2009, IANOŞ [9] 2010, and Brady [10] 2016). However, few studies apply the perspective of balanced territorial development to non-European countries.

The other type of research is related to the effectiveness of policy measures for balanced territorial development. Since territorial development is a broad concept, this type of research mainly analyzes the effect of policy measures on individual units of territory. Most studies deal with policy measures for parts of the territory, such as urban management, rural development, and urban–rural linkage, and a few studies cover the entire territory from a more holistic perspective. Knickel et al. [11] focus on the role of spatial planning and study how it can build mutually beneficial and balanced relationships between urban, peri-urban, and rural areas. Novosák et al. [12] raise the issue that most of the existing studies on territorial cohesion pay attention to some types of territory and suggest a methodology to analyze the territory from the various interrelated aspects of sectoral policies. However, there are few studies sufficient to draw implications for ASEAN countries that should address various development spectrums.

In the field where such studies have been limited, it can be an alternative to derive implications for strategies from lessons learned from the experience of territorial development in a specific country. Korea is one of the countries that has undergone the fastest urbanization and industrialization. Over the process of rapid urbanization and economic growth, Korea has been promoting a step-by-step balanced development and improving territorial policies for it. Korea’s experience can provide the lens for a balanced territorial development framework and implications for a strategic approach. Thus, this study examines the case of Korea to develop strategies for the balanced territorial development of ASEAN countries.

Through the lens provided by Korea’s experience, this study aims to analyze the territorial state and policies of the ASEAN countries. Furthermore, this study seeks to categorize ASEAN countries that exhibit similar territorial states. Such a categorization of ASEAN countries will enable us to derive measures for balanced territorial development strategies effectively. Few studies have been conducted on non-European countries, especially ASEAN countries with diverse development spectrums, to give implications for balanced development; this study can contribute to bridging the knowledge gap.

Section 2 reviews Korea’s experience in developing the strategic types for balanced territorial development. Section 3 explains the research methodology. Section 4 presents the analysis results that demonstrate the conditions of territorial development of ASEAN countries. In Section 5, the ASEAN countries are categorized to develop suitable strategies and policy measures for each type are identified. Such a strategic approach will help improve the effectiveness of urban and regional development in ASEAN countries.

2. Categorization of Balanced Territorial Development Strategies

2.1. Korea’s Balanced Territorial Development

Due to the lack of existing studies on the strategy for balanced territorial development, this study seeks an alternative, which derives types of strategy by reviewing the case of a specific country. Based on existing studies [13,14,15], this study reviews the Korean case of balanced territorial development. During the rapid urbanization, Korea has made a significant effort to implement balanced development policies fit for each era’s economic and social environment [16]. The trajectory of Korea’s balanced territorial development can present meaningful implications for ASEAN countries at different levels of development. In this context, this section analyzes the background, key objectives, and characteristics of Korean territorial development policies for balanced development.

In the 1950s and 1960s, after the Korean war, Korea invested in basic infrastructures, such as building houses, ten major ports, highways, and railways, seeking to establish a foundation for self-reliant economic growth in the process of post-war recovery and industrialization [13,14,15]. As part of the 1st and 2nd 5-Year Economic and Social Development Plans [17,18], projects for infrastructure provision and specially designated areas were carried out.

In the 1970s, to achieve rapid growth by comprehensively mobilizing territorial resources, Korea promoted development based on a growth center strategy centered on the Seoul-Busan Axis to lay the foundation for export-led industrialization, with the emphasis placed on the effective supply of industrial infrastructure and improvement of living conditions [13,14,15]. Key endeavors during this time include establishing industrial and export bases through institutional improvements, such as the enactment of the Act on the Establishment of Free Export Zones and Regional Industrial Development Act and Act on the Promotion of Industrial Base Development, along with the establishment of the 1st Comprehensive National Territorial Plan (1972–1981) [19]. Moreover, the expansion of specially designated areas and the development of new towns for the rearrangement of urban functions were promoted.

The 1980s was a time marked by massive social and economic changes, including the hosting of large-scale international events, mounting pressure to open the market, trade surplus, and democratization movement. During this time, Korea actively implemented policies and plans to address the spatial imbalance that resulted from growth-oriented policies and accelerate balanced territorial development [13,14,15]. Korea’s priority was to limit the growth of Seoul and Busan and disperse the population into other regions, which reflects a shift of focus from the growth center development strategy to the regional center development strategy for metropolitan areas. Some of the key policies in the 1980s include the construction of a heavy chemical industry base and regional industrial promotion districts. Moreover, to attract the population out of Seoul and Busan, the government established Seoul Metropolitan Readjustment Master Plan [20] and classified the national territory into a new urban and regional system while designating and fostering 15 cities as growth centers.

In the 1990s and the early 2000s, the advances in globalization and localization heightened the need to enhance national competitiveness as well as decentralization. In this context, balanced territorial development gained more attention, demanding more autonomy from local governments and private participation in territorial development [13,14,15]. As such, seven metropolitan regions were developed to serve as hubs for regional development to explore the potential of the regions and encourage more private participation to achieve balanced territorial development. Regions deemed to be underdeveloped were designated as Development Promotion Districts. Moreover, each region developed a core managerial function in its specialized area, such as Busan in global trade and finance, and Gwangju in high-tech industry and culture, while the midland and southwestern parts of the country formed new industrial zones.

With a new administration in 2003, the growth-oriented strategy in the past transitioned into a strong, balanced territorial development policy, seeking to enhance the resilience of lagged and declined areas [14,15]. Intensive policy efforts were made for it, such as building a multi-functional administrative city—to which central administrations and public institutions in the Seoul metropolitan area were to be relocated—as well as ten innovative cities, six enterprise cities, and innovation clusters. To this end, the Special Act on Balanced National Development was enacted in 2004 and the Special Accounts for Balanced National Development, implementation bodies such as the Presidential Committee for Balanced National Development, and the 5-Year Balanced National Development Plan [21] system were established, laying the legal and institutional foundation for balanced development.

After the mid-2000s, a new administration sought to foster growth centers centered on 5 + 2 economic regions to achieve economies of scale for national competitiveness. In addition, inter-regional cooperation between economic regions, leading industry promotion strategy, and local specialization projects were promoted. Sixty-three regional daily activity areas were formed to promote regional development that brings about tangible improvements in people’s quality of life, on which flagship rural development and urban regeneration projects were implemented [14,15].

Table 1. Evolution of the Korean territorial policies for balanced development.

Period	Characteristics	Key Territorial Policy
1950s–1960s	Post-war recovery, foundation building for economic growth	- Building key infrastructure - 1st & 2nd 5-Year Economic Development Plan [17,18] - Enactment of the Act for Comprehensive Plans for Construction in the National Territory and the Act on Promotion of Comprehensive Development of Specially Designated Areas (1963)
1970s	Building a territorial system for growth centers, a balanced development strategy to lay a foundation for rapid growth	- 1st Comprehensive National territorial development Plan (1972–1981) [19] - Expansion of production facilities through the development of the Southeastern Maritime Industrial Belt and Gyeonggi Bay Maritime Industrial Region and new towns - Population control in metropolitan areas and the introduction of the green belt system (1971), Regional Industrial Development Act (1971), Industrial Base Development Promotion Act (1973), Industrial Arrangement Act (1977), and Population Redistribution Plan (1978) for fostering industries in major cities in non-capital areas
1980s	Formation of multi-nuclei structure for effective use of national territory	- 2nd Comprehensive National Territorial Development Plan (1982–1991) - Establishment of Seoul Metropolitan Area Readjustment Planning Act (1982) and Seoul Metropolitan Area Readjustment Plan (1982) [20] - Fostering Regional Settlement Areas and growth centers
1990–Early 2000s	Transition to a proactive regional development strategy	- 3rd Comprehensive National Territorial Development Plan (1992–2001) - Act on Balanced Regional Development and Fostering Regional SMEs (1994) - Abolition of the Act on Comprehensive Plans for Construction in the National Territory, which was improved and developed into the Framework Act on National Territory (2003)
After the mid-2000s	Implementation of balanced development policies and development of metropolitan cooperation	- Revision of institutional foundation for balanced development, including the 4th Comprehensive National Territorial Development Plan (2006–2020), Revision Plan (2011–2020) - Presidential Committee for Balanced National Development (2003), 5-Year Balanced Development Plan (2003) [21], Special Accounts for Balanced National Development, and evaluation system - Constructing innovation cities and a new administrative city Fostering 5 + 2 economic regions and inter-regional cooperation

summarizes the above.

2.2. Types of Balanced Territorial Development Strategies

Based on the above data, Korean national territorial policies can be categorized into three strategic types. The first type is the national growth center development strategy, which seeks to lay the foundation for growth by intensifying the advantages of agglomeration economies and approach to balanced territorial development through the spillover effects. This strategy concentrates limited resources on regions with high growth potential. This was the approach of the Korean government towards most of its territorial policies from the 1960s, when the focus was post-war recovery, through the 1970s, when the focus was on forming the basis for rapid growth.

The second type is the regional growth center development strategy, which seeks to transition a unipolar or bipolar structure into a multi-nuclei structure to establish metropolitan regions and balanced territorial development through tailored policies fitting for local characteristics. To address the issue of spatial imbalance in earnest in Korea, policy measures were introduced amid the trend of localization under the administrations in the 1980s–1990s and after the 2010s.

Lastly, distributed growth center development policy seeks to promote balanced territorial development through active engagement of the government to distribute growth centers to narrow regional disparity and also decentralized regional development by introducing policy measures for enhancing the self-reliance of regions. The Korean administration in the early 2000s that made balanced territorial development the national primary agenda belongs to this category.

This study uses these three types of balanced territorial development strategies to categorize ASEAN countries and derive policy measures for their balanced development. After the analysis of territorial conditions of the ASEAN countries, this study revisits this categorization to match the ASEAN countries and policy measures.

3. Methodology

3.1. Analysis Framework

It is vital to understand the current status of territorial development of ASEAN countries to establish strategies tailored to the characteristics of each country. In this study, the current status of territorial development is analyzed in 5 ways. Section 4.1 explores the current status of urbanization and industrialization by looking into if urbanization progresses in line with industrialization. Section 4.2 reviews the size distribution of cities to identify the stages of urbanization and territorial development. Section 4.3 and Section 4.4. analyze the spatial structure and regional development by looking into the location of small and medium-sized cities and the state of regional development within a country. Section 4.5. examines the vision and current policies for balanced territorial development of each country by factoring in the significance of balanced development and regional equity in national agendas as well as the direction of territorial development. The analysis results are incorporated with the types and policy measures drawn through the review of Korean balanced territorial development. Figure 1 shows the analysis framework of this study.

Through the analysis of these five aspects, the current conditions of territorial development and the possibility of balanced development can be assessed comprehensively. First, the trend of urbanization and industrialization are the most basic indicators that provide insight into the level of development in each country and are essential factors in territorial development planning. Since the level of urbanization and industrialization among ASEAN countries varies, based on the current status of urbanization and industrialization, the characteristics of territorial development can be identified. In addition, the transition of industrial structure, from the primary industry to the secondary and tertiary industries, occurs mainly in urban areas. If the benefits of industrialization, such as the growth in GDP, disproportionately fall on certain cities that serve as secondary and tertiary industrial hubs, it may cause an imbalance in territorial development. This study is premised on the idea that the possibility of balanced territorial development is heightened when urbanization progresses in sync with industrialization.

The number of cities by size and population ratio shows the urbanization trend of each country. If an increase in urban population is seen not across all levels of cities but only in the population-related largest city (hereafter referred to as a primary city), it can aggravate the emergence of a primate city, which hinders balanced territorial development. Hence, the size distribution of cities serves as an index that shows the level of balanced territorial development.

Moreover, primary cities often expand into mega-city that extend the level of a single administrative district. If secondary cities exist only as satellite cities within the boundaries of a primary city instead of functioning as a regional growth center, they could fixate uni- or bi-polar spatial structure and, thus, raise the possibility of an imbalance in territorial development.

The regional disparities and geographic concentration indices are direct indications of the level of regional development in each country provided by the Organisation for Economic Co-operation and Development (OECD) [22]. When population and industries exhibit large inter-regional disparity and are concentrated in primary cities, it can be taken as a sign of imbalanced territorial development.

Lastly, the direction of national territorial policy and the significance of balanced development in a national agenda reflects the level of policy commitment to territorial equity. The stronger the policy commitment, the more active a government is in responding to issues of balanced territorial development, and this is an important factor in categorizing balanced territorial development strategies.

3.2. Data Collection and Analysis

Of the ten ASEAN members, eight countries are analyzed in the five aspects of territorial development. Brunei and Singapore are omitted because they are city-states. Figure 2 shows a map of the ASEAN countries included in the analysis.

For Section 4.1 and Section 4.2, statistical data of eight ASEAN countries based on the World Urban Prospects 2018 (WUP) [23] of the UN Department of Economic and Social Affairs (UN DESA) and statistics of international organizations such as the World Development Indicators (WDI) [24] is collected and analyzed in terms of urbanization, economic growth, and industrialization trends. Section 4.1 and Section 4.2 compare trends by country and past vs. present with the collected statistical data.

In addition, this study collects data from each country’s national statistics offices (see

Table A1. Data collected on the spatial structure and the state of regional development.

Country	Source *	Unit	Collected Data
Cambodia	Population Census 2019	21 cities	- population of cities with over 30,000
	Population Census 2019 Human Development Report 2019 (1) Economic Census 2011	25 provinces	- regional population - GRDP per capita - annual sales
Indonesia	UN DESA WUP	33 cities	- population of cities with over 300,000
	Statistical Yearbook 2020	34 provinces	- GRDP and GRDP per capita
Laos	Lao Statistics Bureau website 2015 (2)	10 cities	- population of cities with over 30,000
	Population and Housing Census 2015 Economic Census 2006	18 provinces	- regional population - number of establishments
Malaysia	UN DESA WUP	11 cities	- population of cities with over 300,000
	eDataBank	13 provinces, 3 federal cities	- regional population, GRDP, and GRDP per capita
Myanmar	Population and Housing Census 2014 (2)	77 cities	- population of cities with over 30,000
	Statistical Yearbook 2018 Socio-Economic Report 2017	6 states, 7 regions	- regional population - income per capita
Philippines	UN DESA WUP	31 cities	- population of cities with over 300,000
	Statistical Yearbook 2019	18 regions	- regional population, GRDP, and GRDP per capita
Thailand	UN DESA WUP	28 cities	- population of cities with over 300,000
	Population and Housing Census 2019 National Accounts 2018	6 sub-regions	- regional population, GRDP, and GRDP per capita
Vietnam	UN DESA WUP	11 cities	- population of cities with over 300,000
	Statistical Yearbook 2019 Socio-Economic survey 2018	5 metropolitan cities, 58 provinces	- regional population, GRDP, and GRDP per capita

* Data were collected from (1)UNDP [59] (2020) and (2) the City Population website [60]. Other data was collected from national statistics office websites [61,62,63,64,65,66,67,68] and UN DESA WUP [13].

) when analyzing the spatial structure and the state of regional development included in Section 4.3 and Section 4.4 When needed, this study also utilizes predictive values from international organizations or related institutions. In Section 4.3, The collected data is utilized to map cities and regions to analyze the number and location of growth centers and to examine the current state of regional disparities and geographic concentration. Section 4.4 compares and analyzes country-specific indicators. For Section 4.5, this study collects national documents (see

Table A2. Data Collected on Balanced Development Visions and territorial Policies.

Country	National Plans and Agendas	Territorial Policy Documents
Cambodia	National Strategic Development Plan (2019–2023) [30], The 4th Rectangular Strategy (2019–2023) [31]	National Spatial Planning Policy (2011) [32]
Indonesia	Masterplan for Acceleration and Expansion of Indonesia’s Economic Development (2011–2025) [33], Indonesia Islamic Economic Masterplan (2019–2024) [35], National Medium-Term Development Plan (2020–2024) [36]	-
Laos	Vision 2030, Ten Year National Socioeconomic Development Plan (2016–2025) [37], The Eighth Five Year National Socioeconomic Development Plan (2016–2020) [38]	-
Malaysia	The 11th Malaysia Plan (2016–2020) [40], Mid-Term Review of the 11th Malaysia Plan (2018–2020) [41]	The 2nd National Physical Plan (2011–2020) [42], The 3rd National Physical Plan (2021–2040) [43]
Myanmar	Myanmar Sustainable Development Plan (2018–2030) [44]	National Spatial Development Framework [45], National Urban Policy Framework [46]
Philippines	Vision 2040 [48], Philippine Development Plan (2017–2022) [49]	National Framework for Physical Planning (2001–2030) [50], National Urban Development and Housing Framework (2017–2022) [51]
Thailand	The 12th National Economic and Social Development Plan (2017–2021) [53]	Thailand National Spatial Development Plan (2007–2057) [54]
Vietnam	Socio-economic Development Strategy (2011–2020) [55], Socio-economic Development Plan (2016–2020) [56]	Urban System Development Vision 2050 & Masterplan 2025 [57]

) related to territorial development and conducts a qualitative document analysis of national agendas and policy priorities on territorial development to identify how significant balanced development is in each country.

4. Results

4.1. Urbanization and Industrialization

The results showed the current status of urbanization in ASEAN countries (Figure 3). From 1950 to 2050, the urbanization trend and projections for ASEAN countries rose gradually, or in some cases, they accelerated rapidly. The urban population ratio of eight ASEAN countries increased by 19 percentage points (pp) over the past 30 years, which is higher than the global average of 13 pp. The urban population ratios of Malaysia, Indonesia, Thailand, Laos, and Vietnam increased significantly by 27 pp, 26 pp, 22 pp, 21 pp, and 17 pp, respectively. In contrast, the Philippines, Myanmar, and Cambodia have seen an increase in 0.2 pp, 6 pp, and 9 pp, showing a stalled or slowed increase in the urban population.

The trends of urbanization and economic growth of ASEAN countries over the past 30 years were analyzed based on the 5-year data for the urban population (1990–2020) and GDP (1990–2018; Figure 4). The results show that the per capita GDP for eight ASEAN countries in 2020 was far below the global average of $11,312. With Malaysia (US $11,373) and Thailand ($7274) as the exceptions, the per capita GDP of most countries remained between $1000 and $4000. Although the rate of increase over the past 30 years did not reach the global average, it was recorded as significantly high because of the low value of the ASEAN countries’ per capita GDP. Considering the per capita GDP over the past two to three decades, those of Vietnam, Laos, Myanmar, and Cambodia exhibited 27-, 12.5-, 7-, and 6.7-fold increases, respectively.

Figure 5 shows the urbanization and industrialization trends of ASEAN countries. Cambodia, Myanmar, and the Philippines experienced a drastic shift in industrial structure without a significant change in the population ratio. As the upper graph in Figure 5 shows, while the share of the urban population in Cambodia, Myanmar, and the Philippines saw 8.7 pp, 5.9 pp, and 0.4 pp increases, respectively, employment in their secondary and tertiary industries grew by 45.6 pp, 19.8 pp, and 20.3 pp. In contrast, Indonesia, Laos, Thailand, and Vietnam saw urbanization progress in a way that was relatively directly proportional to industrialization. The increases in the shares of the urban population in Indonesia, Laos, Thailand, and Vietnam (26.1 pp, 20.9 pp, 22 pp, and 17.1 pp, respectively) and employment in secondary and tertiary industries (23.8 pp, 18.4 pp, 9.9 pp, and 29.1 pp, respectively) have both been significant. However, despite the increase, employment in secondary and tertiary industries in Laos is relatively low, at 32%. For Malaysia, the urban population share increased to 50%, while its secondary and tertiary industries accounted for 78% of employment, showing that the country has seen a 27 pp increase in its urbanization rate and an 11 pp increase in its industrialization rate.

As the lower graph in Figure 5 illustrates, the GDP-based analysis showed a similar result to the employment-based analysis in most countries. When the employment rates and GDP shares of secondary and tertiary industries were compared, some countries showed unique signs of industrialization. For instance, Cambodia witnessed a 45.6 pp increase in the employment rate for secondary and tertiary industries, whereas the country’s GDP share increased by a relatively low rate of 19.9 pp. The employment rate of secondary and tertiary industries in Laos remained at a relatively low level of 32% as of 2020; these industries account for 73% of the GDP, which is relatively high, although the secondary and tertiary industries employ a small population. Meanwhile, Indonesia and Thailand saw a huge increase in employment rates but almost no changes in the GDP share of secondary and tertiary industries.

From the GDP share by industry, it can be suggested that Indonesia, Malaysia, and Thailand are undergoing urbanization after industrialization, whereas Cambodia, Myanmar, and the Philippines are undergoing industrialization without the urbanization. Indonesia, Malaysia, and Thailand have seen an increase in the GDP share of their secondary and tertiary industries without the formation of cities that support industrialization. Some cities that house secondary and tertiary industries are reaping the benefits of industrialization, leading to unbalanced territorial development. In Cambodia, Myanmar, and the Philippines, the GDP shares of their secondary and tertiary industries are increasing without urbanization; urbanization will likely come after industrialization, as seen in the cases of Indonesia, Malaysia, and Thailand. This implies that Cambodia, Myanmar, and the Philippines will experience imbalanced territorial development in the future.

4.2. Size Distribution of Cities

ASUS identified the impact of urbanization on economic growth by city size and emphasized the importance of the growth of mid-sized cities with populations between 0.5 million and 5 million. Within ASEAN, there are substantial discrepancies between countries in terms of urbanization, industrialization, and economic growth, and the urbanization trends in each country may vary by city size. This section analyzes the trend of urbanization by city size categories used by the UN DESA for WUP and delineates the characteristics of urbanization. As shown in Figure 6, for the past 30 years, Thailand, the Philippines, and Indonesia have shown a significant rise in the number of cities, with increases of 28, 25, and 11, respectively. In these countries, the numbers of mid-sized cities were 14, 12, and 12, respectively; their primary cities grew to more than 10 million people in the period. In contrast, excluding primary cities, Cambodia, Laos, and Myanmar do not have cities with populations over 0.3 million.

To examine whether development is balanced, it is necessary to consider the characteristics of urbanization, determining what size city the proportion of the urban population is increasing. This section categorized primary and mid-sized cities, described by ASUS, into separate categories; this was done to analyze the ratio of populations to the total population and identify an overall trend of changes, including in the rural population. Figure 7 demonstrates that over the past 30 years, the rural population substantially decreased by 19 pp, and the share in mid-sized cities with 0.5–1 million people and small cities with less than 0.3 million people increased by 8 pp and 7 pp, respectively. The share of the population in primary cities increased by 2 pp, but this figure only represents the population of administrative districts in primary cities.

In terms of the ratio of the population by city size, it is clear the urbanization trend differs by country. In Cambodia, urbanization progressed at a slow pace and was led by its primary city, in which the population has increased by 6 pp. While the share of Indonesia’s small cities increased substantially, from 16% to 39%, the country saw a decrease in the population ratio of its primary city; it is the only country among the eight ASEAN nations with such a result. In Laos, the share of small cities increased by 18%, leading to urbanization in the country. In Malaysia, the population share increased in cities of various sizes. The share of the primary city increased by 13 pp, reaching 24% in 2020, and the share of mid-sized cities also increased by 11 pp. In Myanmar, urbanization progressed at a slow pace, as it did in Cambodia, without significant discrepancies among cities of different sizes. In the Philippines, the share of small cities decreased by 10 pp, resulting in a rise in the shares of cities of different sizes. Thailand saw a 7 pp decrease in the share of cities with less than 0.3 million people, resulting in a rise in population in cities of other sizes; in particular, its mid-sized city population increased by 16 pp. Vietnam saw an increase in the share of cities of various sizes, and in particular, the share of its mid-sized cities increased by 8 pp.

Considering the trends in the population ratios according to city size, urbanization in Malaysia and Cambodia was spearheaded by primary cities; Thailand, Vietnam, and the Philippines by mid-sized cities; and in Indonesia and Laos by small cities. For Myanmar, urbanization was not led by cities of a particular size.

4.3. Spatial Structure of the Territory

To gain a more comprehensive understanding of the current status of the national territory, various facets of urbanization need to be considered. Taking primary cities as an example, the share of the population of an Indonesian primary city accounts for 4% of the total population, which is 9% lower than the average of the eight ASEAN countries. However, Jakarta is a mega-city region that extends beyond the level of an administrative district; the population in the administrative district in Jakarta is 10 million, and in “Jabodetabek,” the Indonesian capital region, it is 30 million. As such, it is necessary to consider whether mid-sized cities exist as satellite cities within the boundaries of a primary city or function as growth centers for other regions. This section explores the spatial structure of the territory of each country to thoroughly investigate the characteristics of territorial development (for the maps, see Appendix B).

Cambodia’s national territory is unipolar-structured, with Phnom Penh at the center. Phnom Penh is the only city in Cambodia with a population of over 1 million, and more than half of Cambodia’s national annual sales take place in this city [25]. Thus, primate city concentration centered around Phnom Pehn, and gaps in regional economic conditions are likely to exacerbate regional disparities.

In Indonesia, half of the population lives in Java. Mid-sized cities with a population of 0.5–1 million are relatively evenly dispersed in Java and Sumatra. There is a wide developmental gap between Java and other islands, and even within Java, the disparity between the Jakarta metropolitan area and the rest of the island is vast, considering that multiple satellite cities of more than 1 million people are located around Jakarta.

Most of Laos’s territory is covered by mountains, and many cities are located in non-mountainous areas or in the Mekong region. In 2019, only 35.7% of the land was urbanized, and all the cities except Vientiane, the capital, and Savannakhet, the second largest city, were small cities with fewer than 100,000 people [26]. Small cities were relatively equally dispersed around the country, but the regional imbalance is expected to widen due to the developmental disparity between the capital of Vientiane and the rest of the country.

The Malaysian territory consists of the Malay peninsula and North Borneo. Cities with over 500,000 people are concentrated in the Malay peninsula; the largest and second largest cities, Kuala Lumpur and Kota Bharu—each with a population of more than 1 million people—are both located in this area. The west side of the peninsula, centered around Kuala Lumpur, is relatively developed and urbanized, while the east side and the Sabah and Sarawak regions are less developed. Kuala Lumpur and Kota Bharu have similar populations, but because Kuala Lumpur is forming a large metropolitan area with neighboring satellite cities, Malaysia is likely to develop into a unipolar structure centered around Kuala Lumpur.

In Myanmar, cities are mainly located along the coastline or in the middle inland area. The country has a prominent unipolar structure centered around Yangon. While Yangon has over 4 million people, most of the cities except Mandalay and Nay Pyi Taw have less than 1 million people. Along with populations, industrial and economic infrastructures are also concentrated in the Yangon region. Thus, the developmental disparity between Yangon and the rest of the country will likely worsen.

The Philippines has a total of 107 cities, and the 11 biggest islands account for 90% of the national territory [27]. Major cities are located in Luzon in the north and Mindanao in the south. Primate city urbanization is intensifying in the Manila metropolitan area. Manila alone has only 1.6 million people, but when adding the neighboring satellite cities, a metropolitan area with more than 10 million people is formed. The biggest city in the Philippines, Quezon, is also located in the Manila metropolitan area. Apart from Manila and Quezon, there are a few mid-sized cities.

Thailand has a unipolar structure centered around Bangkok. With a population of 5 million people, Bangkok is surrounded by satellite cities, each with 100,000–500,000 people. Apart from the Bangkok metropolitan area, small cities with 100,000–200,000 people are scattered around the country. Except for Phuket, the ten cities with the highest Gross Regional Domestic Product (GRDP) rankings are located in the middle part of the country, so economic development has been concentrated in that area [27]. The northern and northeastern regions are generally less developed and have the lowest income levels in the country. The southern region also has low-income levels, except for the region along the Malaysian border. Except for Narathiwat in the south and Mae Hong Son in the north, the lower-income areas tend to be located in the northeastern part of the country.

Vietnam has a bipolar structure centered around Hanoi in the north and Ho Chi Minh in the south. Most cities with a population of over 200,000 are located around Ho Chi Minh in the south and Can Tho. Haiphong, with a population of 1.3 million, is near Hanoi. Da Nag, Hue, and Nha Trang are the only other cities with more than 300,000 people.

4.4. Current State of Regional Development

The OECD published the regional development index, comprising regional disparities and geographic concentration [28], “the extent to which a small number of regions account for a large proportion of a certain economic phenomenon” [29] (p.3); the present study analyzed the state of territorial development based on this classification. Regional disparities of ASEAN countries were analyzed based on the GRDP Gini coefficients and disparities in per capita GRDP, calculated by dividing the most productive region’s value by the least productive region’s value. In addition, geographic concentration was analyzed in terms of the concentration of population and GDP in the primary city.

According to

Table 2. Regional Development Index of ASEAN Countries.

Country	Economic Indicator Gini Coefficient *	Regional Disparity of Economy (per capita) *	Population Concentration in the Primate City *	Economy Concentration in the Primate City *
Cambodia	0.73 (2019)	2.1 × (2019)	12% (2019)	55.4% (2011)
Indonesia	0.58 (2019)	13.7 × (2019)	4% (2018)	17.7% (2019)
Laos	-	22.4 × (2006)	10% (2015)	22.6% (2006)
Malaysia	0.46 (2018)	39.3 × (2018)	24% (2018)	16.2% (2018)
Myanmar	0.16 (2017)	3.0 × (2017)	10% (2014)	-
Philippines	0.57 (2018)	15.6 × (2018)	13% (2018)	37.5% (2018)
Thailand	0.45 (2018)	6.1 × (2018)	15% (2018)	46.9% (2018)
Vietnam	0.19 (2018)	12.0 × (2018)	9% (2018)	18.0% (2018)

* Data sources are referred to in Table A1.

, ASEAN countries mostly demonstrated a high Gini coefficient and wide regional disparities. In Cambodia, because of the large population of Phnom Penh, the per capita GRDP of the most productive region was 2.1 times higher than that of the least productive region, which is relatively narrower than other countries. However, the Gini coefficient is high, at 0.73, because annual sales are mainly concentrated in Phnom Penh. Indonesia’s GRDP Gini coefficient was high, at 0.58, and its disparity of per capita GRDP is also large, with the per capita GRDP of the most productive region 13.7 times higher than that of the least productive region. In Laos, the region with the most firms, Vientiane had 22.4 times more firms than the region with the least firms, so the industrial and economic disparities were wide. Malaysia’s GRDP Gini coefficient was not as large as that of Cambodia, Indonesia, or the Philippines, but the disparity in per capita GRDP was the largest, with the per capita GRDP of the most productive region 39.3 times higher than that of the least productive region, demonstrating drastic regional imbalance. Myanmar has an apparent unipolar structure centered around Yangon and shows a triple disparity, while the regional income Gini coefficient is relatively low. The Philippines shows a high GRDP Gini coefficient and a high disparity of per capita GRDP. In Thailand, the GRDP Gini coefficient and the disparity of per capita GRDP were both wide; the Gini coefficient was 0.45, and the per capita GRDP of the most productive region was 6.1 times higher than that of the least productive region. While Vietnam’s GRDP Gini coefficient was relatively low among ASEAN countries, the country demonstrated a large disparity per capita; the per capita GRDP of the most productive region was 12.0 times higher than that of the least productive region.

Considering the population and GDP levels of the primary cities, ASEAN countries showed an intense geographic concentration. Phnom Pehn, Cambodia, only takes up 12% of the national population, but it was found that 55% of the national sales were concentrated there, demonstrating a high primate city concentration. In Indonesia, the population concentration in the primate city was relatively low, but 17.7% of the GDP was concentrated in this area; thus, it is assumed that the income disparity between the Jakarta metropolitan area and the rest of the country is relatively wide. In Laos, investment and industrial development opportunities were mainly concentrated in Vientiane, with 22.6% of the nation’s firms located there. In Malaysia, 24% of the population lives in the primary city, but the GDP concentration is relatively low among other ASEAN countries, at 16.2%. In Myanmar, 10% of the population lives in a primary city. Thirteen percent of the Philippine population lives in the primary city, but the GDP concentration rate exceeds 37%, which suggests that the economy depends heavily on this city. Thailand’s population concentration in the primary city is around 15%, but the GDP concentration is high, at 46.9%; this shows that a substantial amount of economic activity is concentrated in the Bangkok metropolitan area. Vietnam records a relatively low population and GDP concentration in the primary city, probably because the population and economic activity are relatively evenly divided between Hanoi and Ho Chi Minh.

Most ASEAN countries are structured in a unipolar or bipolar way, with populations mainly concentrated in one or two large metropolitan areas; this causes high regional disparities and geographic concentration. These countries show high urban primacy, in which populations and economic activities are concentrated in a particular city, which is proof of wide disparities.

4.5. Balanced Development Visions in Territorial Policies

As the last aspect of territorial development analysis, this section analyzes how visibly balanced development is handled in national plans and territorial policies. Cambodia’s national plan and specific strategies for territorial development do not clearly identify balanced national development as a primary goal. However, major development strategies and policy documents propose important agendas for balanced development. The National Strategic Development Plan (2019–2023) [30], which was established for the implementation of Cambodia’s top-priority national development strategy, sets practical agendas for balanced development. This includes approving and implementing transportation and logistics masterplans, securing finance for infrastructure, implementing parts of the Industrial Development Policy (2015–2025), and planning land use in the capital area to strengthen urbanization management [31]. Cambodia does not have a separate territorial development plan, but it has set the direction for territorial development within other initiatives, such as the National Spatial Planning Policy (2011) [32]. Its main priority is comprehensive and strategic territorial planning and using land harmoniously with regionally important measures. The policy also emphasizes balance and unity.

Indonesia considers handling balanced development a national issue. The Masterplan for Acceleration and Expansion of Indonesia’s Economic Development (MP3EI; 2011–2025) [33] set regional development, connectivity, and the development of human resources and technology centered on economic corridors as key agendas. It selected six economic corridors as the growth center, developed industrial clusters based on the key resources of each corridor, and secured international connectivity to heighten the synergy among growth centers [34]. However, the second Joko Widodo administration replaced the MP3EI with the Indonesia Islamic Economic Master Plan (MEKSI; 2019–2024) [35]. MEKSI maintains the focus on balanced development. Moreover, the National Medium-Term Development Plan (RPJMN; 2020–2024) [36] chose “regional development to decrease inequalities” as one of the seven main objectives. The plan emphasizes the continuous development of industrial infrastructure for small businesses, special economic zones, and tourism [34]. Indonesia does not have a separate spatial plan, but the Ministry of National Development Planning stresses the importance of regional connectivity in achieving rapid economic growth.

Laos does not have a spatial plan per se, but the 2030 Vision and Ten Year National Socioeconomic Development Plan (2016–2025) [37], established in 2016, sets the path for territorial development. It stresses the construction of basic infrastructure and the decrease in developmental disparities between urban and rural areas. In addition, the 8th Five-Year Socioeconomic Strategy (2016–2020) [38] proposes fostering industries by establishing special economic zones, nurturing industrial personnel, heightening financial efficiency, and utilizing sustainable clean resources as solutions [39]. The strategy reflects the government’s focus on balanced development and has set one of the 20 outputs as “balanced regional and local development,” prioritizing developing underdeveloped regions.

Balanced development is one of Malaysia’s key national objectives. In the 11th Malaysia Plan (2018–2020) [40], among the six strategies, “Strategy 1. Enhancing inclusiveness towards an equitable society”, ”Strategy 5. Strengthening infrastructure to support economic expansion,” and “Strategy 6. Re-engineering economic growth for greater prosperity” included specific guidelines for balanced territorial development. The importance of balanced development also increased with the Mid-Term Review of the 11th Malaysia Plan (2018–2020) [41] to solve regional disparities and inequalities. Apart from this plan, the country has also established National Physical Plan (NPP). This accurately reflects the national spatial objectives and strategies and serves as a guideline for government planning at different levels. All NPPs deal with balanced development as the main agenda, but NPP-2 [42] stresses equity more than NPP-1 does. NPP-2 underlines sustainable, holistic, inclusive, and balanced development through physically connecting urban and rural areas. Balanced urban and rural development and the improvement of access and connectivity between urban and rural areas are also the main objectives of NPP-3 [43].

The Myanmar Sustainable Development Plan (2018–2030) [44], a top national development plan, sets eight action plans for “Strategy 1.2 Promote equitable and conflict-sensitive socio-economic development throughout all States and Regions”. Such measures as decentralizing the management of development projects, promoting inclusive growth and job creation in conflict zones, and strengthening connectivity between underdeveloped regions and growth hubs fall under these action plans. The National Spatial Development Framework [45], a draft for the future direction of spatial development, also calls for a national urban system that sets forth a spatial structure and considers the main urban networks and transportation axes. The suggested urban system is divided into four tiers—namely, national strategic growth, regional cities, agro-industrial cities, and border towns/other special function settlements [46]. Each hub is connected through the transportation corridors for economic growth, and such transnational networks as the Greater Mekong Subregion (GMS) Economic Corridors and ASEAN Highway are considered. Finally, the National Urban Policy Framework [47] lays down the vision and priorities of Myanmar’s urban policy and stresses that maintaining a connection and balance between the urban and rural areas is the most important of the six key objectives.

Vision 2040 [48], the long-term national plan in the Philippines, stresses the role of cities as a driving force for economic growth and poverty reduction, but it does not deal with the issue of balanced development. The Philippines Development Plan [49], made to realize Vision 2040, includes the National Spatial Strategy (NSS), which provides a policy framework for urban development, infrastructure development, disaster mitigation, environmental protection, and resource preservation. It stresses the need for a network that connects metropolitan areas, regional hubs, and small-town hubs. The Plan strives to solve the issue of inequality by connecting late starter regions and developed regions. However, it opposes the equal dispersion of development, which leads to a poor economy and other inefficiencies. Reflecting economic growth, demographic patterns, and spatial features, the NSS proposes the most desirable spatial allocation according to the different economic, social, legislative, and environmental conditions. The National Urban Development and Housing Framework (NUDHF; 2017–2022) [50] also stresses the importance of balanced development, although this term is not specifically mentioned. The NUDHF pursues urban space as an inclusive, open, connected, and collectively resilient community and emphasizes social and environmental factors in the process of development. The National Framework for Physical Planning (NFPP) (2001–2030) [51] deals with issues regarding physical planning and suggests policy options for physical resources. It seeks to facilitate decentralization via regional concentration, strong ties between urban and rural areas, resource-based regional development, and the establishment of a mechanism for effective regional development.

Thailand formulated the 9th and 11th National Economic and Social Development Plans to develop ten economic zones centered around economic corridors connected with GMS countries and border regions [52]. Following this, Thailand established Thailand 4.0 to nurture the ten key national industries and develop the Eastern Economic Corridor, which is a major part of Thailand’s 12th Plan (2017–2021) [53]. In this plan’s ten strategies, “Strategy 9. Strategy for regional, urban, and economic zone development” is linked to balanced development. It stresses each region’s strengths to utilize its geographic and social features and to strengthen the base of the manufacturing and service industry, presenting different development paths for each region. Thailand has a National Spatial Development Plan (2005–2057) [54] and aims to achieve balanced development according to different regional potentials. The main contents of the plan can be summarized as the development of economic corridors and ASEAN’s economic hub, the establishment of a hierarchical structure among regional hubs by designating central and specialized cities in each region, and the connection of the logistics system and economic zones.

Vietnam’s national plan places the top priority on building an industrial hub for economic development, followed by achieving balanced development. Among 12 policy directions, balanced development was indirectly reflected in Development Orientations 2, 5, and 6 in Vietnam’s Socio-Economic Development Strategy (2011–2020) [55]. These Development Orientations emphasized the even dispersion of industries across the nation for balanced and effective development between regions. For example, “6. Harmoniously and sustainably develop regions, build up new urban and rural areas” divided the country into different areas and set specialized directions for development in each area. The goal of the Five-Year Socio-economic Development Plan (2016–2020) [56] also reflected the country’s interest in balanced development. As part of the plan, “Task 2. Promote economic restructuring associated with growth model innovation, improving productivity, efficiency, and competitiveness,” set out specific goals, such as agricultural restructuring related to new rural development, industrial restructuring for modernization, and services industry development. Moreover, “Task 3. Economic region and economic zone development” set the direction of development for the whole country, as well as for each region, and emphasized the connection between territorial development and the development of major economic zones. Vietnam has laid out a Master Plan for Vietnam’s Urban System Development to 2025 and a Vision to 2050 [57], which works as a normative document for all territorial plans. This document aims to gradually establish and enhance Vietnam’s urban system by applying the urban network model, seeking regionally balanced development, creating a connection between urban and rural areas, promoting stable and sustainable growth based on an adequate spatial structure, reasonably utilizing natural and land resources, and so on.

Table 3. ASEAN Countries’ Vision for Balanced Development.

Country	Direction of Balanced Development	Indication of Balanced Development	Importance of Equality	Major Territory Policies
Cambodia	Logistics system improvement, new growth engine development, urbanization management	Indirect goal	Low	- Implement Cambodia’s Industrial Development Policy [31] - Approve and implement master plans on transport and logistics [31] - Establish land-use planning in metropolitan areas [31]
Indonesia	Designation of 6 growth centers, continuous development of industrial infrastructure	Top-level goal	High	- Develop industrial clusters based on economic corridors [34,36] - Work together with countries around the globe [34,36] - Focus investment on transport infrastructure [34,36]
Laos	Infrastructure development for industrialization, development gap reduction between urban and rural areas	Sub-level strategy goal	Medium	- Foster growth of industries through the development of special economic zones [37,39] - Expand stable income in rural areas and support commoditization of products [37,39] - Construct and maintain roads in rural areas [37,39]
Malaysia	Balanced urban growth and comprehensive rural development, connections and accessibility between urban and rural areas	Top-level goal	High	- Establish an integrated public transport system connecting urban and rural areas [40,42] - Attract businesses in underdeveloped areas and establish growth centers [40,42] - Implement national development plans to build core infrastructures [40,42]
Myanmar	Connecting growth hubs with underdeveloped areas	Sub-level strategy goal	Medium	- Connect function and infrastructure between urban and rural areas [44,45] - Improve living conditions and create job opportunities in rural areas to foster economic development [44,45]
Philippines	Establishment of a network between big cities, regions, and lagged regions	Indirect goal	Low	- Improve commute from home to work [49,51] - Connect central areas with underdeveloped regions [49,51] - Does not support equal distribution [49]
Thailand	Growth centered on economic corridors and achieving specialization of regions	Sub-level strategy goal	Medium	- Develop the Eastern Economic Corridor to expand sea routes in the eastern region [52,53] - Implement Thailand 4.0 to foster ten target industries [52,53]
Vietnam	Regional development to build a foundation for growth, reasonable distribution of industries	Indirect goal	Medium	- Develop urban system and set development direction for each region [57] - Develop growth centers in economic zones for a spillover effect [56,57] - Emphasize the concentration of investment resources [56]

summarizes the results, and data sources refer to Table A2.

The analysis of the documents on ASEAN’s national plans and territorial policies shows that there are many similarities between the countries’ visions and policies. First, the national plans include policies that aim to boost the important values of balanced development and present inclusiveness and fairness in planning guidelines, whether explicitly or indirectly. Second, countries set forth fostering special economic zones and building industrial complexes that support industrialization as important policy tasks and aim to secure connectivity at the pan-ASEAN level. In addition, they emphasize physical and functional links between regions and promote the establishment of transport and industrial infrastructure as the main national projects. Finally, they emphasize the importance of building urban systems based on specific growth centers and devising a comprehensive approach in terms of national spatial planning.

Even with similar policy goals, countries differ in deciding which goals they consider most important, and such decisions highlight the characteristics of each country. The countries can be categorized into three groups based on how they conceptualize balanced development—namely, countries that have balance as a high-level goal, countries that consider it a sub-level strategy goal, and countries that aim to promote balanced development indirectly by developing specific regions. Indonesia and Malaysia promote strong, balanced development as part of their high-level goal in the national plan, while the rest of the countries’ directions for balanced development focus more on regional development than on reducing the gap between regions. All the countries also consider how the connection between ASEAN member states can help their national plans, but they differ in how actively they use this connection. Such countries as Cambodia, Myanmar, and Laos, where the primary industry takes up a significant portion, set the vitalization of rural areas and connect urban and rural areas as strategic goals.

5. Discussion

Comprehensively considering the above results of five analyses, this section categorized eight ASEAN countries to identify a suitable balanced territorial development strategy (

Table 4. Types of ASEAN’s Balanced Territorial Development Strategy.

Type	Country	Characteristics of Territorial Development	Priorities
National growth center development strategy	Myanmar, Cambodia, Laos	∙ Low urbanization and a high percentage of the primary industry ∙ Main issues are rural area development and facilitating linkages between urban and rural areas ∙ Need to establish industrial complexes for the diversification of the economy and improve logistics to expand trades ∙ Preemptive policies to prevent the formation of primate cities	National territorial plan, agro-industrial complex, national industrial complex and infrastructure development, special economic zone, product support facility, logistics infrastructure, Restricted development zones
Regional growth center development strategy	Vietnam, Thailand, Philippines	∙ Uni- or bipolar concentration of population and industry during urbanization ∙ Promotes a transition to a multi-nuclei structure in national territorial plans ∙ Major strategies consist of specialization strategy for each region and establishing an urban system and hierarchy	Metropolitan area development plan, capital area management plan, regional specialization, development of new cities, metropolitan infrastructure (transportation, environment), regional industrial complex, special economic zone
Distributed growth center development strategy	Indonesia, Malaysia	∙ Higher levels of urbanization and industrialization compared to other ASEAN countries ∙ Extreme concentration of population due to primate cities ∙ Sets balanced development as a high-level goal in national plans and promotes equal regional development	Special accounts for balanced development, development of administrative and innovative cities, social services and basic infrastructure, and services for lagging areas)

). This section also presents the priority measures of each strategy that each country can adopt (

Table 5. Measures for balanced territorial development by type.

Type	Objectives	Measures	Target Area
National growth centers	Promoting industrialization and diversifying the economy	National territory plan	All national territory
		Industrial complex and product support facility	National growth centers (outskirts of primary city, secondary cities, port cities, and border towns)
		Special economic zone	National growth centers
		Metropolitan plan	National growth centers
		Logistics infrastructure	Connecting primate city with growth centers
	Preventing the formation of primate city	Regulations for primate city (green belts, limiting the size of factories)	Primary city
	Connecting urban and rural areas	Agro-industrial complex	Secondary and smaller cities
Regional growth centers	Establishing a city system and a hierarchy between cities	National territorial plan	All national territory
		Logistics infrastructure	Connecting between regional growth centers
	Differentiated development for each region	Metropolitan infrastructure (Transport, water supply, sewage, waste disposal)	Regional growth centers (a central city by region) and nearby areas
		Metropolitan plan	Regional growth centers
		Special economic zone	Regional growth centers
		Development of new cities	Regional growth centers (excludes a primate city)
		Industrial complex and production support facility	Regional growth centers (excludes a primate city)
	Managing the growth of a primary city and megacities	Plans to improve metropolitan areas	Primate city, megacities
		Regulations (levying fines on large buildings, land suitability assessment system)	Primate city, megacities
Distributed growth centers	Building a foundation for balanced development	Balanced development plan	All national territory
		Balanced development policy (special accounts, special bodies)	All national territory
		Logistics infrastructure	Connecting a primate city with regional growth centers and distributed growth centers (strategic secondary cities)
	Dispersion of population and industry	Administrative city (capital relocation) and development of new towns	Distributed growth centers
	Developing underdeveloped areas through cooperation	Building innovation clusters (research complex, tourism and leisure complex, etc.)	Distributed growth centers
		Specialized support for each region (promotion zone, special development zone, etc.)	Distributed growth centers
		Improving social services and infrastructure	Small cities, underdeveloped areas

), which have been proven to be successful through Korea’s experience in balanced territorial development. In Korea’s territorial development path, there are various lessons in achieving the policy goal of balanced development. This study intends to utilize this territorial development path in Korea only to categorize strategies and to derive priority policy measures. We emphasize that this study aims to present a strategy that can be considered first by categorizing ASEAN countries and not to compare Korea and ASEAN countries directly.

Cambodia, Laos, and Myanmar can adopt the national growth center development strategy, in which the priorities are connecting urban and rural areas, diversifying the economy, and adopting preemptive measures to prevent the formation of primate cities. Vietnam, Thailand, and the Philippines can adopt a regional growth center development strategy, and its priorities lie in growth management, creating cities with a multi-nuclei structure, and promoting policies to foster the development of metropolitan areas. Indonesia and Malaysia can adopt a distributed growth center development strategy, and its priorities are relieving the regional gaps, evening out regional development across the nation, and adopting policies to strengthen the region’s capability for self-reliance.

Though these priorities are presented according to the characteristics of territorial development, each country should consider the local and historical context to implement these policies. To take an industrial complex as an example, the location of an industrial complex may differ according to which strategy a country adopts. Countries that adopt a national growth center development strategy may prioritize building industrial complexes in suburbs of the primary city, secondary cities, port cities, or border towns, while those that adopt a regional growth center development strategy may consider a central city in each region to be the priority. Policies regarding primary cities may also differ according to each type. The national growth center development strategy type can prevent the formation of primate cities by adopting preemptive policies such as designating green belts, but the regional growth center development strategy type needs to actively manage growth through regulations such as levying fines on large buildings and adopting land suitability assessment system. Countries with distributed growth centers need a direct policy to disperse the population concentrated in primate cities, such as capital relocation. Measures such as building an agro-industrial complex can be adopted in 8 different ASEAN countries whose industry is largely based on their primary industry, but priority could be given to countries with national plans that emphasize the connection between urban and rural areas.

6. Conclusions

Sustainable development emphasizes stage-skipping, meaning that developing countries should not repeat the same mistakes developed countries make [58]. Korea has made many mistakes in the process of its national territorial development. If anything has been learned from the country’s past experience, it is that taking a preemptive approach to balanced territorial development leads to a reduction in future costs that may arise from imbalanced development. Balanced territorial development can promote the sustainable development of ASEAN countries.

However, there are several limitations to this study. As explained in the introduction section, due to the absence of previous studies on the categorization of balanced development strategies, this study tried to derive the types by examining the Korean experience. Concerning this methodology, there is a problem with the usefulness of applying Korea’s territorial development path to the ASEAN countries. A question like ‘Should ASEAN countries follow Korea’s development path?’ or ‘Shouldn’t an ASEAN country with the type of national growth center development characterized by low urbanization and low industrialization adopt a policy measure for the type of distributed growth center development in which the government actively intervenes in decentralization?’ may arise.

We emphasize that an introduction of policy measures should be tailored to the local condition, taking into account the policy goals and possible side effects, rather than applying Korea’s development path as it is. We also indicate that the priority policy measures are not intended to apply exclusively to any particular type. For example, the establishment of industrial complexes has been promoted as an important policy in all ASEAN countries and can be used as an important measure in all three types. However, depending on the type of balanced development strategies, the location (outskirts of primary city, a central city by region, or strategic secondary cities) and specific targets (economic diversification, differentiation of regional development, or linkage with underdeveloped regions) may vary.

This study analyzed the state of ASEAN countries’ territorial development from five aspects to suggest a suitable strategy and policy measures. However, further research is needed to apply each measure to a country in accordance with local conditions. First of all, for an ASEAN country to carry out a customized balanced development policy, an in-depth study targeting only that country is necessary. In this in-depth study, more implications can be drawn through direct comparison with Korea’s territorial development path. Second, there should be more research on the effectiveness of specific subjects or policy measures for balanced development. For example, the urban-rural divide is an issue that is often mentioned in existing studies [2,3]. Through more studies on the effectiveness of the policy measures presented in this study, more effective, targeted, balanced development strategies can be suggested.

The key to balanced territorial development of ASEAN countries lies in the local capacity to utilize relevant policies and technologies that can be reflected as key issues in their territory initiatives. The results of this study demonstrate that ASEAN not only needs to address the development gap between countries but also the regional gap within each country. ASUS identifies various problems that result from rapid urbanization, such as unequal economic growth and urban expansion, and predicts that these problems will affect all aspects of the growth of mid-sized city areas. In this context, regional gaps and imbalanced territorial development in the ASEAN countries are of concern, which can be used to predict the demand for balanced territorial development. Under the theme of balanced territorial development, measures that meet the demand of ASEAN are highly called for.