Resilience in Food Systems: Concepts and Measurement Options in an Expanding Research Agenda

Abstract

The idea of “resilience” increasingly appears in development dialogue and discussion of food systems. While the academic concept of resilience has roots in diverse disciplines, climate change and the coronavirus disease 2019 (COVID-19) pandemic have led to a rapid intensification of interest in the concept as it applies to food systems. Both the broad conceptual roots and the swift increase in attention pose dangers of conceptual dilution, contradiction, and confusion as agronomists and other analysts of food systems incorporate the resilience concept into their work. In this publicly funded research, the authors present the results of an extensive search of literature and subsequent analysis. The overview examines conceptualizations of resilience more broadly, followed by a similar review within the food systems domain. The authors consider connections among related concepts under the broader umbrella of food security, such as vulnerability and risk, and discuss challenges and opportunities in the investigation of food system resilience. The review of concepts serves as a precursor to an investigation of measurement options in a rapidly expanding body of empirical research, as measurement should flow clearly from conceptualization. The analysis here presents various resilience measures at different levels and breaks down their components as they apply to food systems, identifying commonalities and divergences. The authors identify a glut of resilience conceptualizations and measurements but indicate avenues for consolidation and precision. The range of options means that researchers can likely find suitable existing subconcepts and measurements for their own work across many different types of shocks. The authors also discuss policy and practical applications, including connections to the United Nations’ Sustainable Development Goals and food system responses to climate change and pandemics.

1. Introduction

The effects of phenomena such as climate change, locust swarms, and the coronavirus disease 2019 (COVID-19) pandemic have underscored the global need for resilient food systems in recent years. New shocks and long-term stressors have exerted pressure on food systems, necessitating an improved understanding of how food systems might successfully deal with such adversity. Fortunately, the concept of resilience has a rich history of development across a wide range of disciplines, including in studies of food systems more recently. However, as with any multidisciplinary or interdisciplinary subject, conceptual dilution and stretching threaten to undermine utility. Such conceptual stretching is particularly problematic as researchers have moved into the measurement of resilience at different levels. Therefore, the present paper supplies an overview of the development of the concept of resilience and its associated measurement, both generally and specifically within the study of food systems. As food system resilience has garnered more attention among policymakers at national and international levels, researchers have developed an expanding array of cross-national resilience indices to supplement those that assess food system resilience on more localized levels. The hope is that this overview can elucidate core ideas behind such measures and can thereby serve as a foundation for scientific investigation and practical applications in agronomy and related fields that examine food system resilience.

In some ways, resilience might seem like a repackaging of older ideas, but the new emphasis on integrating resilience as a core theme requires a reorientation of thinking. Certainly, the fields of agronomy and agricultural economics have a history of studying topics such as vulnerability, risk, and recovery as they relate to events that include price shocks and drought [1,2,3,4]. The knowledge generated by this earlier scholarship must inform the present moment. However, the realization of resilience as a cross-cutting theme in agronomy means that concepts and measures must be capable of addressing many different types of shocks and capable of working at different levels. Making progress on food system resilience will require clear objectives and indicators, tasks that will benefit significantly from clear conceptualization. Scientific progress is difficult to assess without clear foundations. Such foundations are crucial as research on food system resilience moves into more complicated terrain that includes coincident risks, tradeoffs between resilience and other goals, and tradeoffs between local resilience and global resilience [5,6,7,8]. Similarly, policies for food system resilience require clear baselines for making projections, for identifying areas for improvement, and for evaluating the performance of programs. Measurement, whether qualitative or quantitative, is crucial for scientists, governments, and donors. Further, the problems facing food systems are complex and multidimensional. Such problems necessitate a sophisticated response. The response thus far has also been complex, covering domains such as food security, food system sustainability, and climate-smart agriculture. Distinguishing resilience from these other major topics in food systems is also important for clarifying objectives. The food systems literature has advanced enough at this juncture in its consideration of resilience to allow for a careful examination of the extant knowledge as well as of challenges and areas for additional work.

We have conducted a conceptually focused, systematized review of the literature that included academic and gray literature. Our searches emphasized scientific databases and search engines. Furthermore, we have conducted the review in an iterative manner, following up on new lines of inquiry (e.g., related concepts and subconcepts) and identifying the most recent publications in a rapidly evolving field. In conducting our review, we funneled from the most general to most specific topics. The following research questions guided our review process: How did the resilience concept originally evolve across disciplines? How did measurement of resilience progress across disciplines? How has the resilience concept evolved in the study of food systems? How have researchers and practitioners approached measurement of food system resilience?

This paper proceeds in sections that move from general conceptual work to specific measurement challenges in the food systems domain. In Section 2, we examine the multidisciplinary history of the resilience concept and its measurement, as well as investigate conceptual disagreements and consider the relationships among resilience and similar concepts. Further, we provide a summary of the general substantive components of resilience, categorized into six different capacity areas. In Section 3, we build directly on the previous section by delving more specifically into the application of resilience to food systems. The section begins with an overview of existing conceptual work on food system resilience, linking this work to the six capacity areas covered earlier and adding two capacity areas specific to food research. We then summarize existing work on the measurement of food system resilience, similarly discussing remaining issues in measurement. Finally, in Section 4, we summarize our findings and discuss how our work fits into agronomy research more broadly. We also consider implications of existing resilience work for policymaking and evaluation in food systems.

While we identify many different conceptualizations and measurement approaches, our overview and analysis provide a solid foundation for integrating resilience concepts and measurement into food system research and practice. Researchers can build on a strong body of resilience conceptualization and can identify strengths in existing measurement approaches that would benefit the specific contexts of their own research. Prominent policy and evaluation processes globally will continue supplying an impetus to make resilience a core part of thinking about food systems.

2. Resilience Concepts and Measures Generally

The concept of resilience emerged in multiple fields as a term describing the processes or state of withstanding stress and recovering after a disturbance. The term appeared in the study of ecosystems [9], social infrastructures intersecting with the natural environment [10], objects and systems in the physical sciences [11], and individuals’ psychological development within the behavioral sciences [12]. Scholars in these disciplines disagree about where the term first gained currency and how it should be applied or understood, often arguing that transporting the term into other contexts warps or dilutes its meaning [13,14,15]. Some of these arguments go so far as to say that the alteration and dilution of the term has rendered it meaningless.

Nonetheless, the term “resilience” has recently experienced a surge in attention across disciplinary boundaries, and clarity about its application could enhance its utility greatly in fields such as agronomy. Conceptually, resilience offers a framework for thinking about agriculture, urban planning, environmental engineering, disaster relief coordination, community organization, and a host of other areas in addressing contemporary threats to the stability of systems. Given the pervasive, recurrent, and often widespread nature of many contemporary shocks, researchers and practitioners have increased attention on community resilience and on the ability of an entire network or social structure to withstand and recover from disturbance.

2.1. Conceptual Disagreements

In this subsection, we briefly explore three intellectual debates that have arisen as the concept of resilience evolved beyond its original meanings and applications. The first concerns whether and how resilience can be extrapolated from discrete entities to larger populations. The second considers whether resilience is a quality or outcome that can be reached or is a dynamic process that is harder to observe. The last ponders whether resilience requires a prompt return to a predisaster status quo or adaptation to a state of higher functioning.

First, early applications conceptualized resilience at the individual or discrete object level, such as a person coping with psychological adversity or an object resuming its normal form and function after disruption. This limited scope simplified the assessment of resilience, particularly when combined with the view that resilience is an observable trait or outcome—as discussed below. Pushing back against broader usage, some researchers working at the intersection of engineering and ecology argued that the term held too much inherited meaning to be used in analyzing the dynamics of social networks and ever-changing populations [13]. Scaling the concept of resilience to deal with social–ecological systems required significant expansions and made objective assessment more complicated. Most notably, community resilience is not the simple sum of individual resilience in the system [16,17,18,19]. Further, risk and vulnerability are not equally distributed across system components or community members, and risky internal dynamics in one part of a system or community can easily negate resilience in other parts, thus making the system nonresilient overall [20,21]. One response to this challenge is to focus on high and non-disparate levels of functioning, access to support, quality of life, etc., among members of a population [18]. When analyzing the resilience of complex systems that include policy and institutional configurations, human behavior, and market forces—all of which are influenced by external shocks and internal workings of other components—the resilience of the system depends critically on resilience among constituent parts but cannot be treated simply as the aggregate of those parts.

A second point of contention in applying resilience to communities or systems is the question of whether resilience is a quality or attribute to be possessed or is instead a dynamic process. One straightforward way to define and measure resilience is as a function of the degradation in quality of services or functioning, as well as the time until full operation is restored [22]. Less clear is whether resilience is the outcome of that process (i.e., the speedy restoration of normal functioning) or can be assessed dynamically in observing the process of recovery itself. Earlier definitions typically adhered to an outcome-based view, focusing on the act of bouncing back from or absorbing impacts—conjuring images of an object’s elasticity [23,24,25]. In such a view, resilience is an attribute that can only be observed after disruption. Wildavsky, for example, defined resilience as “the capacity to cope with unanticipated dangers after they have become manifest” [25] p. 77. Outcome-based views necessarily treat resilience in a reactive way, placing limits on its relevance to predisturbance planning or capacity building.

As a result of these limitations, resilience is now conceptualized more commonly as a dynamic strategy or framework or as a constant process of refining a network of adaptive capacities [18,26,27]. Such an approach often emphasizes the identification of common characteristics of resilient entities [14]. Despite the focus on dynamism, this rethinking also permits the assessment of community or system resilience at a given point in time and allows communities to build resilience proactively. Norris et al., in a thorough and careful overview of conceptual issues tied to community resilience, define resilience as “a process linking a set of adaptive capacities to a positive trajectory of functioning and adaptation after a disturbance” [18] p. 130. Their approach has gained considerable currency across disciplines, almost to the point of serving as a common definition. In what follows, we use their definition as a baseline as well.

The third point of contention is whether the hallmark of a resilient system is the return to a normal, predisaster functioning or is an adaptation that markedly changes functioning, particularly if that means an improvement in quality. Advocates for a return to normal functioning emphasize resumption of the rhythms of daily life [28] or a return to normal [17]. Some envision resilience as resistance (see below) or as an insulating buffer capacity, meaning that systems display resilience by maintaining the status quo in the face of a disturbance [26]. Along these lines, resilience is “the ability of a system to remain stable … the function, structure, and identity of the resilient system do not change” [29] p. 346.

More in line with conceptualization of resilience as a dynamic process, others propose that resilient systems and communities “not only deal with adversity but also reach a higher level of functioning” [30] p. 760. Resilient communities, for example, “maintain or enhance residents’ quality of life following a shock” [31] p. 130, learn from risk events quickly and inclusively [32], or develop new trajectories for the future [33]. Such an understanding—which is growing more common in the natural hazards and disaster recovery literature—complicates the measurement of resilience because possible trajectories for learning and change are practically infinite. Conversely, previous conceptualizations allowed for quantifying resilience simply as the time required for a system to return to its predisaster status quo functioning. Norris et al. describe the relevant difference as one between “engineering resilience”, which “makes a system return to one pre-designed state”, versus “ecological resilience”, which “allows for many possible desirable states that match the environment” [18] p. 130. The authors further note that the latter is more relevant for human communities, organizations, and societies [18]. Ultimately, altering our understanding of resilience to encompass not only recovery but also growth in the wake of disturbances seems more in line with the normative hopes for resilience as a framework for adapting to contemporary social challenges. This is certainly true of food systems, which necessarily involve human beings in a variety of ways. However, we also acknowledge that growth is not always necessary if a system was performing well prior to a shock.

2.2. Related Concepts

This subsection considers linkages among resilience and similar concepts relevant to food systems. Figure 1 and

Table 1. Definitions for Figure 1 illustration.

Concept	Definition	Example Source(s)
Risk	Likelihood and potential severity of a negative shock	[34]
Resilience	“A process linking a set of adaptive capacities to a positive trajectory of functioning and adaptation after a disturbance”	[17,18] p. 130
Resistance	Ability to block or minimize shocks, preventing negative consequences	[18]
Recovery	Return to conditions that existed prior to a shock	[35]
Adaptation	Response to major environment changes and/or political and economic shocks	[36]
Vulnerability	An undesirable interaction between risk and readiness potentially producing negative outcomes	[37]
Sustainability	Meeting the needs of the present without compromising the ability to meet future needs	[38,39]
Food security	A condition encompassing the availability, accessibility, utilization, safety, quality, and nutritional adequacy of food	[40,41]

provide basic definitions and shows what happens in a food system that deals successfully with negative systemic shocks—more from a conceptual than a causal standpoint. Food system resilience is roughly in the middle of the conceptual chain shown in the figure. As a theoretical model, the figure excludes some level of real-world complexity. A fully accurate rendering would include more arrows. The purpose of this figure is to show the positioning of resilience relative to other concepts. Starting at the bottom of the figure, risk has a substantial history in disciplines that include economics, agricultural economics, disaster management, and psychology. Sometimes referred to as “risk exposure” or just “exposure”, risk incorporates potential shocks into the model. Higher-risk situations suggest more frequent and/or more severe shocks. How the system deals with these shocks is the focus of this paper.

Successful food systems address shocks through either resilience or resistance. Some scholars have conceptualized resistance as an element of resilience, with resilient communities absorbing shocks to minimize their initial impact on functioning, thereby speeding recovery time [16]. Accordingly, resilience is easier to achieve when disturbances are minimized or repulsed in the beginning. However, other scholars differentiate clearly between resilience and resistance, with the latter repulsing the shock in a way that prevents any dysfunction in the first place [18]. Figure 1 adopts this approach.

Successful response to a negative systemic shock sometimes requires recovery and other times requires adaptation. For example, the negative consequences posed by a civil war might be historically limited and require recovery for a food system. Alternatively, many negative climate change influences on food systems are long-term factors that necessitate adaptation to new conditions. Adaptation sometimes involves the adoption of new procedures and technologies [36], such as those embodied in climate-smart agriculture approaches [42]. Thinking along these lines fits well with the “adaptive capacities” terminology of resilience. As discussed earlier, recovery and adaptation in response to a shock are definitional indicators of system resilience. As such, they appear with resilience in Figure 1 and contribute to either improvement or sustainability of the food system. Improvement, again, would involve a higher level of functioning or one better adapted to the environment, while sustainability would involve meeting present needs without compromising the future.

Vulnerability and resilience have a close relationship, sometimes characterized as being opposites on a single spectrum [18,24]. However, we believe a clearer conceptualization views vulnerability—a state of potential in common usage—as a combination of risk and readiness [37] that indicates sensitivity to a shock [43]. A system is vulnerable when the risk–readiness combination is undesirable (e.g., high risk and low readiness). Adaptive capacities of resilient systems are often also features of readiness to deal with shocks. However, some systems do not need extensive readiness to deal with certain shocks. For example, a city hundreds of miles inland has less vulnerability to a hurricane, regardless of adaptive capacities, due to low risk. Alternatively, high-risk situations require significant adaptive capacities to reduce vulnerability. Consequently, a community can improve resilience either by improving adaptive capacities or by reducing risk [44]. Figure 1 includes a zone of “vulnerability interactions” in which problematic combinations of shocks, available resources, and responses could interact to produce negative outcomes.

The topic of resistance is an important one on its own given its potential to make resilience unnecessary. While the present paper focuses on resilience, the strong connection between the two concepts allows for certain observations and conclusions. Many of the adaptive capacities in Figure 1 might also constitute “resistance capacities” that could repel shocks. Correspondingly, one could envision a parallel box with such capacities and an arrow to resistance in Figure 1. Strong resistance characteristics—as a form of readiness—would make a system less vulnerable to shocks. Future research could investigate overlap and differences between the concepts of resilience and resistance.

Sustainability scholars often point toward elements that echo definitions of resilience. For example, authors talk about “dynamic preservation, over time, of the intrinsic identity of the system among perpetual changes” [45] p. 958 or “the ability of a system to maintain productivity in spite of major disturbance” [46] p. 35. However, sustainability is distinct in its focus on meeting the needs of the present without compromising the ability to meet future needs [38], which is not an explicit component of resilience. Therefore, as shown in Figure 1, food system resilience may contribute to sustainability, but sustainability is a function of more than just resilience. Factors such as resource and ecosystem stability also contribute to the sustainability of food systems.

Finally, food security is an outcome of improvements to and sustainability of a food system—along with many other factors. Due to the breadth of the concept, food security definitions often directly incorporate the different components that contribute to food security, such as the availability, accessibility, utilization, and stability of food [41]. Figure 1 positions these definitional elements as conceptual contributors to food security. This list is not comprehensive due to the complexity and breadth of the concept of food security.

2.3. Substantive Components of Resilience

Many authors have grouped the adaptive capacities that contribute to resilience into general substantive categories. These categories appear in the lower left-hand corner of Figure 1. Again, a resilient system utilizes adaptive capacities in a way that turns shocks into positive functioning. This subsection discusses six capacity categories relevant to food systems.

First, economic capacities revolve around a system’s ability to deal with shocks both with minimal macroeconomic welfare losses and in ways that reduce microeconomic vulnerability [47]. Past studies have focused primarily on the diversity and volume of resources or on employment opportunities in a community as indicators of economic resilience [18,33,48,49]. Notably, such characteristics may work at cross purposes. For example, agricultural industrialization may increase efficiency and productivity while crowding out smallholder enterprises that can offer critical diversity in crop and livestock variants [50]. In the social–ecological systems literature, the influences of economic interdependence can reduce resilience by eroding community autonomy and increasing exposure to volatility [16,51], though others argue that economic globalization offers benefits for resilience, including classic gains from trade [52,53]. Additionally, a review of the recent economics literature on global supply chains highlights ways in which varying degrees of market competition and scales of production across industries may inhibit businesses’ ability to form robust and resilient supply chains [7].

A second set of capacities are political or institutional in nature. In short, the structure and quality of government institutions create political capacity, which is strengthened by institutional transparency and efficiency in allocating resources. Contributing to resilience are inclusive and responsive political institutions that empower citizens and are committed to transparency and honesty, creating trust in times of crisis [30,52,54]. Governments might build resilience by increasing access points to make participation easier and to deploy resources more efficiently [18,19,22,33,48,49]. Metrics range the gamut from more qualitative assessments [33,48,54] to subjective evaluations provided by interviews and survey data [30] to measures of institutional efficiency [22,49].

Social capacities are a third category that includes social capital and civic engagement, as well as demographic factors that shape communities’ adaptation and ability to draw on supports. Different forms of social capital within communities help them to access resources and to engage collectively in resisting and responding to disaster [55]. Communities are most resilient when social capital produces systems that are more inclusive and that prioritize creative and collective decision making [53]. Social capital also enables communities to draw effectively on government resources [32,52,53]. In short, social capital mitigates the social effects of disasters, helping to maintain community cohesion, participation, and trust in institutions [28]. However, close-knit communities may overestimate their ability to cope with disasters, shunning outside support or ignoring risk warnings [31]. Social dimensions of resilience are built across levels, with individual resilience and risk exposure as well as the demographic makeup of the community affecting its collective ability to withstand or recover from disaster [18,26]. Studies identify more vulnerable and less resilient subpopulations, or ones disproportionately harmed by shocks and to whom resources facilitating recovery are less readily available [19,51]. Common measures assess the structure of support networks, the sociodemographic composition of a community, levels of volunteerism or civic engagement, and a sense of connection to place or cultural identity [18,30,33,48,49,54,56].

The physical/infrastructural capacities of resilience, a fourth category, include the technical capacity of vital infrastructures and resources in response to disturbance. Resilient communities require infrastructures to deliver water, fuel, medical support, and other resources reliably at all times, and particularly under pressure [22,48]. Physical infrastructure must be well maintained and should have redundancies to guarantee continued functioning or a prompt return to functioning [22,49]. More resilient communities also develop physical infrastructure that reliably provides access to quality education, healthcare, public transit, and leisure spaces antecedent to crises, all of which should increase the resistance capacity of a community and facilitate social dimensions of resilience [28,48,54]. Some measures focus on the quality of construction in the built environment [22,49], while others include the share and diversity of renewable energy sources serving a community, accessibility of hospitals or doctors per capita, and sustainability of systems controlling drinking water and wastewater [48]. Yet other indicators tap into the infrastructure shaping community resilience, including educational attainment and the proportion of land devoted to public leisure [28,54].

A fifth category, informational capacities, includes both tangible communication infrastructure and the more subjective element of imputing meaning or framing a shared narrative around shocks and responses. The systems for relaying information about crises and for crisis response can make communities more resilient by increasing preparedness and by directing individuals toward relevant resources [18]. Greater efficiency and accuracy in communication result in greater capacity to absorb shocks and a more rapid return to normal, as qualified entities credibly disseminate information through wide-reaching platforms [26]. Further, the transmission of information must build a narrative that creates shared meaning that is relevant to the affected parties [18,19,54]. Some measures look objectively at communication infrastructure that provides citizens with information about risks and recovery strategies [18,26] or the degree to which adaptive strategies are rooted in empirical data collection [48,49]. Other measures focus on the extent to which communities can develop a shared understanding of problems and possible solutions grounded in local context and culture [18,33].

Environmental capacities, a sixth category, are at the core of many analyses of social–ecological system responses to natural disasters and climate-driven shocks. Resilient communities use their environmental resources to withstand or bounce back from disaster. Dependence on natural resources and intrinsic characteristics of the natural environment affect resilience [16,51]. Although geography may leave some communities more exposed to shocks, the environment may also provide resources critical to recovery [29]. While some analyses consider environmental resilience qualitatively through descriptions of how societies interact with the land, more generalizable ways to observe environmental resilience hinge on tangible measures of land usage or environmental degradation, as well as access to key natural resources such as clean air/water and healthy soil [48,49,54,56].

Another common approach in thinking about adaptive capacities is to examine their properties, including robustness, redundancy, and rapidity [18,22]. Robust resources maintain functioning under stress. Redundant resources are substitutable when disruption occurs. Rapidly deployable resources reduce response and recovery timelines. Communities and systems can move from transient dysfunction to resilient, adapted functioning when resources are sufficiently robust, redundant, and rapidly deployed [18]. Certainly, these properties are also observable qualities of specific adaptive capacities in the categories just outlined.

3. Application of Resilience to Food Systems

Food system researchers have made notable efforts to incorporate resilience as a framework or as a strategic aim for policymaking into their research. Food system researchers favor the conceptualization of resilience as a dynamic, multiscale process. Food systems are social–ecological systems made up of complex feedback loops that “encompass social, economic, political, institutional, and environmental processes and dimensions” [57] p. 18. Given a focus on climate change, this literature tends to emphasize adaptation and transformation of systems under pressure, resulting in improved functioning post-shock rather than a return to the status quo. This section addresses how existing notions of food system resilience comport with broader conceptualizations of resilience and adds two capacity categories specific to food systems. This section also examines interactions between resilience and other concepts in Figure 1 within the food systems literature.

3.1. Food System Adaptive Capacities

Resilience in the food systems literature echoes past definitions, emphasizing “the ability of a system and its component parts to anticipate, absorb, accommodate, or recover from the effects of a hazardous event in a timely and efficient manner by ensuring the preservation, restoration, or improvement of its essential basic structures and functions” [45] p. 959. Similarly, Tendall et al. put forward a working definition of food system resilience as “capacity over time of a food system and its units at multiple levels, to provide sufficient, appropriate and accessible food to all, in the face of various and even unforeseen disturbances” [57] p. 19. While such definitions clearly incorporate recovery and adaptation trajectories following a shock, they also extend into the conceptual space of food security. The most pressing disturbances covered in this literature are natural disasters and market shocks resulting from global temperature rise and increasing climatic variability. Food system resilience emphasizes capacities that translate loosely to the six capacities of resilience reviewed earlier.

Economic factors (#1 in Figure 1) relevant to resilience sometimes cut both ways. The positive of greater food access from increasingly global food supply chains is accompanied by negative externalities in the form of pollution, food waste, and biodiversity pressure [45]. Similarly, freer global trade can generally address regional shortages of food [58], but increased food supply does not automatically translate to reduced hunger or increased food security due to political and distributional issues [59,60]. However, lower levels of poverty and higher income relative to food prices can increase food system resilience [60]. Some analysts see the helpful characteristics of redundancy and rapidity in having local food resources to fall back on, increasing resilience in the event that international supply lines are damaged [61].

Politically (#2), food system researchers have also focused on the organizational structure of different levels of government. For example, national and international agreements regulating subsidies or agricultural policy can stifle local decision-making autonomy, making systems less resilient [62]. Further, the introduction of climate-smart agriculture or other policies designed to make food systems more resilient requires buy-in both from local users and political elites across levels of government, so political institutions that influence or facilitate such buy-in are important to resilience [63]. Researchers generally recognize the importance of high-quality governance and policy decisions to food system resilience. For example, policy interventions by national governments contributed in major ways to variation in food supply disruptions among Asian countries at the start of the COVID-19 pandemic [64]. Some researchers point toward the need for governments to be more “adaptive” if they want to help build resilient food systems [65].

The social capital (#3) capacity of resilience is echoed in arguments that local farmers should interact with multiple suppliers and retailers, building a large, redundant network that they can draw on to survive shocks. Further, food system resilience must consider cultural or social appropriateness of foods, as foods deemed inappropriate locally may not contribute as much to resilience [19,20]. Moreover, food insecurity is significantly more common in both female-headed households and financially insecure households across African countries in the wake of COVID-19′s disruption of food systems [66]. The emphasis on gender as a key factor in food system resilience parallels scholarship examining gendered components of agricultural production [67].

Physical infrastructure (#4) emerges in discussion of food system resilience via the structures in place to produce and distribute food, noting that more resilient food systems develop ways to intensify food output through technological innovation [20]. Further, equipment for planting, harvesting, and processing must be robust and/or redundant under normal functioning and when subject to disturbances. The infrastructure that connects urban and rural areas, shaping the delivery of foods to markets and consumers, also influences resilience [20,60,68]. Moreover, access to electricity and other infrastructure shapes production and profit for food producers and enables farms to resist some climate-related shocks [50].

The increasing digitization of economic transactions and the agricultural sector combine to increase informational (#5) capacities of food systems, building in redundancies for communication and transactions and making food production technologically more robust [69]. Moreover, growing movements to spread food literacy seek to expand knowledge about healthy food choices for consumers, with those informational pathways altering patterns of supply and demand. Further, information transmission by public officials to food producers, retailers, and consumers regarding public health guidelines has major consequences for the functioning of food systems [70,71].

Food system resilience is closely linked to environmental (#6) capacity, in that the biophysical and ecological characteristics of a place are key food system drivers. These characteristics influence the quality, quantity, and diversity of food production possible in an area. Environmental characteristics shape baseline agricultural inputs into food systems and can place constraints on supply chains and market interactions. In line with resilience work focused on the intersection of social factors with built and natural environments, community interactions with the land and the natural resources around them directly influence food system functioning.

Food system resilience by necessity incorporates elements not included in other conceptualizations of resilience. Agricultural (#7) capacities should contribute to robustness, redundancy, rapidity, and adaptability [57]. Food production diversity [72,73] is an aspect of capacity, as more diverse food systems are viewed as more robust and adaptable in the face of shocks and also supply redundancy to hedge against crop failure. Similarly, diversity of output markets for farmers contributes to resilience [72]. Further, countries using improved agricultural technologies are better able to respond to shocks quickly and effectively, thus demonstrating greater resilience [74].

While health capacities appear in a limited way in resilience studies elsewhere, a focus on nutritional (#8) capacities is rather specific to food system resilience. The basic idea is that the current nutritional situation influences the extent to which a food system can handle a shock. For example, per capita food production (often roughly measured in terms of food energy) and storage provide a picture of the nutritional situation, as do food costs and expenditures [60,72]. Child malnutrition can similarly provide information about the capacity of the society to meet basic needs [74]. Finally, food imports might constitute a vulnerability if they indicate dependency, though imports can also serve as diversified or redundant pathways improving resilience [72].

3.2. Related Concepts and Complications

This subsection reviews relationships between resilience and similar concepts in the food systems literature. The concepts of resistance and recovery appear in food systems research, which emphasizes nonlinear patterns of growth and exploitation, conservation, and reorganization or renewal [62]. Studies incorporate resistance through preparedness for shocks, intensification or diversification of food production processes, or building in redundancies by developing several nonexclusive linkages with suppliers, farmers, retailers, shipping routes, etc. [59,60]. However, studies of food system resilience often focus less on resistance and more on adaptiveness and ability to transform. Such research notes that resistance to change in the face of various food system drivers (e.g., changes in policy, demand, economic or environmental conditions) may actually preclude positive adaptations [57].

Sustainability often appears in tandem with resilience in food system studies. An early definition of agroecosystem sustainability [46] looked much like contemporary resilience definitions. A newer definition of food system sustainability emphasizes protections for producers, retailers, and consumers, meeting current needs for nutritious food supply without compromising the ecosystem’s ability to produce food in the future [39], thereby differentiating itself from resilience. Tendall et al. frame the two as complementary concepts, with resilience helping to achieve sustainable performance [57]. Arguably the biggest distinction in the food system literature is that sustainability is described as a normative concept requiring stakeholders to agree upon subjective goals, whereas resilience and vulnerability are more descriptive system properties [45].

Food system resilience and vulnerability often appear together as well. Some food systems researchers argue that more resilient systems are less vulnerable by definition [45]. A more typical view is that vulnerability is a product of interactions between resilience and risk. Figure 1 reflects such thinking. While food system resilience is partly a function of risk (as argued earlier), the adaptive capacities of the food system may contribute to high resilience, thereby lessening vulnerability.

A challenge in applying resilience frameworks to food systems is variance in relevant time frames of shocks. Climate change may contribute to near-instantaneous shocks such as floods—a finite event from which a community or system can recover. However, climate change also serves as a chronic stressor to food systems, altering seasonal temperature and precipitation patterns, gradually raising sea levels, or steadily reducing arable land. Many of these shocks occur simultaneously or cumulatively on different time scales, compounding and making it difficult to isolate or identify resilience to a particular external disturbance [20].

Further, the dynamic nature of resilience and the complex interactions among networked adaptive capacities limit our ability to disentangle its causes and effects [30]. Food systems are complex social–ecological systems with infrastructures that govern access to water, energy, land, and human labor, and their functioning depends on ecological factors, human behavior, and various other institutions. Failure or vulnerability in any one of these components can have difficult-to-quantify consequences for the functioning of another component, particularly as these consequences may not be immediate or predictable [20]. Both conceptually and empirically, assessments of food system resilience should account for the qualities and behaviors of the constituent parts of food systems and approach them holistically to give a full picture of risk and adaptive capacities.

3.3. Measurement of Food System Resilience

This subsection examines approaches for measuring food system resilience at different levels and with different degrees of dynamism. Cross-national measurement has tended to focus on broader concepts, such as food security and sustainability, that incorporate resilience as a subconcept. One national-level approach [73,75] operationalizes resilience using two composite indicators: Food Production Diversity [76] and the Notre Dame Global Adaptation Index (ND-GAIN) [74]. The latter measures exposure and sensitivity to climate change as well as readiness to deploy resources and use them for adaptation [74]. ND-GAIN looks like a composite index characterizing resilience in its own right, though it assesses the two components of readiness and vulnerability. Gustafson et al. introduced this two-component (i.e., Food Production Diversity and ND-GAIN) measure of resilience in food systems and applied it to nine countries [73], while Chaudhary et al. extended to 156 countries [75]. However, this measure produces relatively low cross-national variance [75].

Table 2. Resilience elements in national-level measurement approaches.

	Chaudhary et al. [75]	Seekell et al. [60]	EIU’s GFSI [77]	FAO [72]
(1) Economic
Wealth distribution		X	X
Economic readiness	X
Dependence on natural capital	X
(2) Political/institutional
Political commitment to adaptation			X
Governance readiness/risk management	X		X
(3) Social
Demographic stress	X
Social readiness	X
Sociocultural wellbeing	X		X
(4) Physical/infrastructural
Energy infrastructure	X
Transport infrastructure	X			X
(5) Informational
Information and communication technology	X
(6) Environmental
Exposure to climate change impacts	X		X
Freshwater resources	X	X	X
Land health			X
Marine health			X
Arable land resources		X
Ecosystem stability	X
(7) Agricultural
Food production diversity	X	X		X
Output market diversity				X
Yield gap/projected change	X	X
Agriculture capacity	X
Agricultural water risk			X
(8) Nutritional
Food imports	X			X
Stored food				X
Malnutrition	X
Waste and loss reduction	X
Cost of food				X
Per capita food expenditures		X
Caloric production per capita		X		X

Notes. Chaudhary et al. measure food system sustainability, so some indicators capture components of sustainability other than resilience [75]. The authors use ND-GAIN to measure resilience, but shaded cells do not appear in ND-GAIN.

displays how indicators from four cross-national measures map to the eight capacity categories of resilience discussed earlier.

Another cross-national index of food system resilience, produced by Seekell et al., scores up to 96 countries from 1992–2011 on metrics of food access (via income distribution and purchasing power), biophysical capacity, and production diversity [60]. Data availability might now allow for greater coverage, particularly with socioeconomic indicators. Several of their indicators are related to earlier measures by the Food and Agriculture Organization of the United Nations (FAO) and other agricultural development practitioners.

The Economist Intelligence Unit’s (EIU’s) Global Food Security Index (GFSI) incorporates a category on “Sustainability and Adaptation” as a main pillar [77]. Within this pillar, indicators mark countries’ exposure to climate-related shocks; the quality and quantity of land, water, and biodiversity; political measures showing commitment to adaptive strategies; and disaster risk management [77]. Covering 113 countries, the GFSI pillar is the most comprehensive cross-national measure of food system resilience. Worth noting is that some of the categories indicated in Table 2 for the EIU’s GFSI are indicators in pillars other than the Sustainability and Adaptation pillar.

The final column in Table 2 captures a recent cross-national measurement approach for agrifood systems’ resilience from FAO. The approach utilizes various indicators in assessing four areas of food system resilience: the domestic agricultural production system, availability of food for consumers, food transportation infrastructure, and economic access to food [72]. Redundant pathways and diversity of food sources are important elements of the approach.

Researchers have also measured food system resilience at levels more granular than the country level.

Table 3. Subnational resilience measures.

Measure/Approach	Description	Source(s)
Self-Evaluation and Holistic Assessment of climate Resilience of farmers and Pastoralists (SHARP)	Small-group interview data collected by tablet with quick data visualization tools, indicating smallholder, farmer, and household perceptions; refined version is SHARP+	[62,78]
Resilience Index Measurement and Analysis (RIMA) I and II	Assessment of household-level adaptive capacity, social safety nets, assets, and access to basic services as four core pillars of resilience; measures direct and indirect resilience	[79]
International Development Enterprise (iDE)’s Market System Resilience Index (MRSI)	Assessment of resilience in market system, especially in rural areas; combines market structure, connectivity, and support, as well as dynamic functioning and redundancy	[80]
Resilience and resilience capacity measurement options (produced for the United States Agency for International Development)	Light, intermediate, and full approaches for measuring resilience at the household and community levels, along with specific measures for absorptive capacity, adaptive capacity, and transformative capacity	[44,81]
World Bank Group rating system	Assessment of exposure and adaptive capacity in individual development projects	[82]
Operationalizing food system resilience in three dimensions	Assessment of resilience dimensions of “buffer capacity, self-organization, and capacity for learning and adaptation” at subnational level	[40] p. 434

summarizes six different approaches for such measurement. These measures typically operate at the household, community, or regional levels. The measures have different purposes and emphases but typically incorporate adaptive capacities.

A remaining measurement concern is that context specificity (e.g., time, space, shock) and variance across farming systems introduce a complexity that makes the development of general measurement tools difficult [83,84]. Some researchers have pushed for context-specific measures of resilience for individual systems [62], while others have argued for standardized metrics that convey approximate measures of resilience across agroecosystems, countries, or regional contexts [60,75]. Researchers will have to determine acceptable trade-offs between specificity and generalizability. A related concern is that tools useful for generalizing across spatial and temporal contexts cannot really capture multiscale feedback loops or variables having different impacts in different time periods [83]. Researchers have aimed to capture such dynamism by employing methods such as scenario diagramming [20], social foresight modeling [68], and discrete choice models to draw inferences about resilience under varying climate forecasts [50]. Similarly, Cabell and Oelofse’s behavior-based qualitative indicators of resilient agroecosystems are iteratively linked to phases of adaptive cycles and feedback mechanisms [62].

4. Discussion

The primary objective for this paper was to provide an overview of the conceptualization and measurement of resilience both generally and within the domain of food system resilience. We proceeded with a systematized review that focused on identifying what is known and what the current limitations and lines of future inquiry might be [85]. In so doing, we have created a solid foundation for continued scientific progress in studying food system resilience—a topic presently attracting great interest. A lesson from this exercise is that the study of resilience generally struggles from a glut of conceptualizations and measurements, threatening to reduce conceptual utility. However, the differences are not wholly irreconcilable, and the food systems literature on resilience has shown greater restraint. While the food systems literature boasts options in terms of the level of analysis, the dynamism of the approach, and relationships with other key concepts, the basic underlying ideas tend to be similar. Further, the diversity in measurement strategies can serve as an asset. Collectively, the different approaches look across levels and subdimensions and examine resistance, recovery, and transformation in slightly different lights. This diversity enables the up-front clarification that researchers increasingly want, given the term’s widespread usage and resulting ambiguity [14,24]. Further, some measures offer ways to observe and assess resilience as a dynamic process with complex feedback loops between drivers and outcomes. Which measures or modeling strategies are most appropriate depends on the audience and goals of each project. The variety of measurement efforts—capturing dynamics of resilience in so many ways and across levels of individuals, households, communities, systems, and countries—should allow researchers to select an option appropriate to their objectives [57]. The notion of resilience is likely to become an integral part of food system research and practice moving forward. Certainly, agronomists can benefit from the considerable conceptual work already done. Such work, if appropriately understood and heeded, provides a strong base for scientific advancement. However, the context-dependence of resilience and the need to refine measurement approaches represent opportunities for careful future thinking and research [86]. The present paper has emphasized the linkages between concepts and subsequent measurement, as well as the nuances of measurement approaches at different levels. As such, we believe this paper serves as a strong complement to parallel work very recently published with a greater focus on conceptualization questions [86,87,88].

Clear conceptual and measurement work are essential precursors to answering more complex questions about contexts, levels, and tradeoffs as they apply to food system resilience. Investigation of specific challenges and contexts has value, as does thinking more broadly about general resilience, but the approaches have some logical differences [89,90]. The coincidence of different risks is another important context that may influence resilience conceptualization and measurement [5]. Integration across levels is yet another advancement in the literature, and one that poses challenges. Cross-level interactions can be complex. For example, vulnerabilities at a lower level could be obviated by higher-level policies or infrastructure, as in the case of national-level protections or subsidies to absorb lower-level losses and dysfunction. Finally, researchers have begun thinking about resilience tradeoffs, with productivity, efficiency, and cost on the one hand trading off with resilience goals such as nutritional value, environmental health, crop diversity, and lower susceptibility to shocks [6,7,90]. Similarly, researchers have begun thoroughly investigating the resilience of supply chains, including tradeoffs inherent in local versus global supply chains [7,8,90,91]. Technology, too, can serve as an asset for building resilience, but we must pay attention to potential unforeseen consequences [92]. Technologies and innovations come with their own susceptibilities and risks.

Conceptualization and measurement of food system resilience also have implications for policymaking and evaluation. Again, clarity is necessary for establishing priorities, making projections, and evaluating subsequent performance. We see implications of conceptualization and measurement for larger efforts in development and food security as well. The Sustainable Development Goals (SDGs) reference food systems and food system sustainability in several objectives. The relationship between resilience and sustainability in food systems is of critical importance for guiding international development projects that target agricultural sectors and global food markets [65]. Likewise, the attention that intergovernmental organizations such as World Bank and FAO have already dedicated to understanding and measuring resilience suggests that this will be crucial to development projects moving forward. However, research gaps remain in investigating food system resilience in low- and middle-income countries [93].

Finally, the COVID-19 pandemic has prompted renewed focus on food system resilience in response to global health shocks. Researchers have thought critically about applying different resilience components, thereby highlighting socially vulnerable demographic groups and analyzing the role of global supply chains, digital information transmission, political institutions, and other factors shaping food system resilience in response to the pandemic [64,66,94,95]. Food system resilience in the face of major pandemic disruptions—especially coinciding with challenges posed by climate change—offers crucial lessons while generating new and important questions.