Duurzaamheid verkopen: Effectiviteit en ontwerp van vrijwillige standaarden in globale landbouw- en voedselsystemen

Respecting social thresholds and staying within planetary boundaries is a major challenge, especially in the agrifood system. The growth of complex global value chains has intensified these challenges, creating gaps in sustainability governance in global agrifood trade. In response, various sustainable value chain initiatives have emerged, including voluntary sustainability standards (VSS), aimed at addressing these challenges. VSS, such as Fairtrade, Organic, and GlobalGAP, are widespread market-based instruments, covering up to 15-44% of the global harvested area for commodities like cocoa and coffee, and thus hold significant potential to enhance sustainability in global food systems. VSS set criteria related to sustainable production practices, which economic actors can voluntarily adopt to signal their commitment to sustainability. However, there is considerable skepticism about the effectiveness of VSS in achieving their sustainability goals. Reviews of impact studies conclude that the socioeconomic and environmental effects of VSS adoption can be positive, negative, or neutral, with identification challenges, contextual factors, and variability in VSS design identified as key considerations. A better understanding of how these factors influence VSS effectiveness can therefore help to improve their impact. Despite a rapidly growing body of scientific literature on VSS, major knowledge gaps remain. This dissertation aims to advance our understanding of VSS effectiveness by examining their micro-level welfare impacts, macro-level deforestation and export effects and trade-offs, and the role of contextual factors and VSS design in shaping these outcomes. Chapter 1 introduces the broader context of sustainable value chain initiatives and VSS. It presents a conceptual framework for understanding VSS effectiveness, proposing that their effectiveness depends on both adoption and additionality, which are in turn influenced by VSS design, demand, and contextual factors. The chapter provides an overview of existing evidence on VSS effectiveness and design and identifies research gaps. Based on this overview, the chapter outlines the research objectives and structure of the dissertation, as well as an overview of the empirical data used in the analyses. Chapter 2 analyzes the channels of effects through which VSS affect farmer welfare of family farms in Peru. Specifically, it examines three key revenue determinants and evaluates their relative importance in explaining how VSS contribute to net farm revenue—as a proxy for farmer welfare. Using nationwide data from Peru's National Agricultural Survey, covering five years, multiple commodities, and VSS, we apply multiple mediation within-effects models via structural equation modelling, alongside maximum likelihood and instrumental variable (IV) estimators. We find that prices, rather than yields, are the primary channel through which VSS affect net farm revenue. However, higher prices cannot offset increased production costs, resulting in zero net revenue gains. No significant effect through yields is observed, but we identify a large potential effect to increase net farm revenue. The study also reveals heterogeneity in the effects by VSS and crop type, with crops certified under VSS that use quality-based price differentiation showing the largest impact on net farm revenue through price effects. From a policy perspective, the findings suggest that for VSS to effectively improve economic sustainability, attention should be focused on improving standard design. Key areas for improvement include explicitly integrating land productivity objectives, incorporating incentive-compatible practices and pricing mechanisms, reducing implementation costs, and tailoring VSS design to local contexts. Chapter 3 examines how the design of VSS affects farmer welfare among family farms in Peru. The analysis focuses on three design mechanisms: rules and enforcement, capacity-building, and market incentives. Additionally, the chapter explores how membership in a farmer organization shapes these effects. Using data from Peru's National Agricultural Survey, covering four years, multiple commodities, and various VSS, we employ multiple mediation within-effects models via multilevel modeling and Bayesian estimation. The results highlight that VSS design matters for VSS effectiveness. The analysis finds that "carrots", in the form of market-based incentives and capacity-building, rather than "sticks", in the form of rule enforcement, are the primary governance mechanism through which VSS affect net farm revenue—as a proxy for farmer welfare in Peru. However, these effects are limited and do not lead to significant overall welfare gains. Market-based incentives, particularly price premiums and market access, are the most important, while the minimum price in Fairtrade supply chains does not significantly influence farmer welfare. Capacity-building, notably through technical assistance, followed by training and market information, has the largest effect on farmer welfare, although access to credit has no effect, despite its potential. In contrast, "sticks," such as the enforcement of good agricultural practices (GAP), do not significantly affect welfare or yields, contrary to expectations. However, potential welfare-enhancing effects are found through the adoption of certain GAPs, and an increase in capacity-building positively influences the enforcement of GAP-related rules. Additionally, membership in a farmer organization strengthens market-based incentives and plays a more significant role in capacity-building than VSS alone. The findings underscore the importance of balancing "carrots" and "sticks" in VSS design to promote broad adoption, ensure compliance, minimize oversupply, and safeguard price premiums, thereby enhancing economic sustainability. Chapter 4 analyzes whether VSS are associated with more stable welfare effects over time for both family farms and agro-industry in Peru. The analysis focusses on inter-annual relative price and yield volatility, and how this affects net farm revenue volatility. Using a nationally representative farm survey of Peru covering five years, multiple VSS and commodities, we employ between-effects models, along with ordinary least squares, matching, and IV estimators. The results show that VSS adoption is associated with lower yield volatility (for all farms), lower price volatility (for family farms), and lower cost volatility (for agro-industry), leading to stabilized net farm revenue for family farms only. From a policy perspective, these findings highlight the potential of VSS to enhance economic sustainability and resilience for certain producers, while emphasizing the need for complementary policies to support non-certified producers and to tailor VSS design to specific crop and farm types. Chapter 5 examines whether VSS reduce commodity-driven deforestation at the landscape level, considering both direct and indirect land use change and potential spillovers, and analyzes how VSS design shapes their effectiveness. Additionally, it analyzes whether VSS can mitigate trade-offs between halting commodity-driven deforestation and fostering export growth in forest-risk commodities. The analysis relies on secondary commodity-driven deforestation attribution data, combined with export data, and certification data from standard-setting organizations for 12 VSS across 7 commodities, 9 years, and 125 producing countries. We employ within-effects models, along with Poisson pseudo-maximum likelihood and IV estimators. The results indicate that, while previous studies suggest that VSS moderately reduce deforestation on-farm, their effectiveness at broader spatial scales is more limited. However, VSS weakly mitigate deforestation-export trade-offs by reducing deforestation per unit of export value and volume, indicating relative decoupling. The effects vary across commodities and VSS, with reductions in both deforestation and deforestation-export trade-offs observed in the palm oil sector, Rainforest Alliance, and Roundtable on Sustainable Palm Oil. These effects are linked to higher deforestation and enforcement stringency, with the latter proving more important for improving VSS effectiveness. In contrast, in the banana, cocoa, and coffee sectors, Organic, UTZ and Fairtrade International, weak increases in deforestation and/or worsened or non-significant changes in deforestation-export trade-offs are observed. Non-significant effects are found in other sectors and VSS. To maximize the potential of VSS in mitigating deforestation-export growth trade-offs, the findings highlight the importance of prioritizing requirements that address indirect land use dynamics, ensuring robust enforcement and monitoring across several spatial scales, targeting deforestation-risk areas, and stimulating the uptake of certified commodities. Chapter 6 concludes by synthesizing the main findings and reflecting on the limitations and implications for future research, standard-setting organizations, value chain actors, and policymakers. This PhD concludes that VSS have the potential to enhance socioeconomic and environmental sustainability and resilience for certain producers and commodities, but that the potential depends critically on strengthening and tailoring VSS design. However, VSS design requires a careful balancing act, as design choices face tensions between compliance, demand, and adoption.