Econ Papers Daily / 期刊论文
自愿性可持续标准与经济及生态结果：来自卢旺达咖啡部门的小组证据
Voluntary sustainability standards and economic and ecological outcomes: panel evidence from Rwanda’s coffee sector
摘要
Voluntary sustainability standards (VSS) promise consumers that certified products are produced under sustainable conditions. While the literature assessing the effects of VSS has expanded considerably, most studies rely on cross-sectional data, thereby providing only a snapshot in time, and focus on single sustainability dimensions, limiting our understanding of whether improvements in one dimension are accompanied by unintended negative effects in another. Moreover, little is known about the extent to which VSS duration influences outcomes, even though sustainability-related improvements may take time to materialize. Our study addresses these gaps using a three-wave panel dataset from Rwanda’s coffee sector to examine how VSS and their duration are associated with economic and ecological outcomes. We distinguish between state and civil-society VSS , which are developed and monitored by organizations such as governments or NGOs, and industry VSS , which include both company-owned standards and multi-stakeholder initiatives with strong industry involvement. We combine household-, buyer-, and plot-level data and draw on a unique dataset of 844 households, 102 plots and 48 coffee buyers. We find that only state and civil-society certification is positively associated with economic outcomes such as coffee yield, prices, profits and returns to land, while longer certification duration under both VSS types is associated with improvements in most economic outcomes. Ecological results are mixed. While state and civil-society certification and its duration are positively associated with shade tree outcomes, we do not observe similar associations for industry VSS. For both schemes, we find no positive associations with animal diversity outcomes. The findings highlight that VSS should be understood as a long-term process in which sustainability improvements materialize gradually. They also point to current limitations in the ability of VSS to achieve environmental objectives, particularly under industry VSS. More broadly, our findings emphasize the importance of considering time dynamics and multiple sustainability dimensions when assessing VSS effectiveness.
中文摘要
自愿性可持续标准（VSS）向消费者承诺，认证产品是在可持续条件下生产的。尽管评估VSS效果的文献已大幅扩展，但大多数研究依赖横截面数据，因而仅提供某一时点的快照，并聚焦于单一可持续性维度，这限制了我们对某一维度的改善是否伴随另一维度非预期负面效应的理解。此外，尽管与可持续性相关的改善可能需要时间才能显现，但关于VSS持续时间在多大程度上影响结果，仍知之甚少。本研究利用卢旺达咖啡部门的三期面板数据集来弥补这些空白，考察VSS及其持续时间如何与经济与生态结果相关联。我们区分由国家与公民社会制定和监督的VSS，以及行业VSS，后者包括企业自有标准和行业深度参与的多利益相关方倡议。我们结合农户、买家和地块层面数据，并依托一个包含844户农户、102个地块和48个咖啡买家的独特数据集。我们发现，只有国家与公民社会认证与经济结果（如咖啡产量、价格、利润和土地回报）呈正相关，而两类VSS下更长的认证持续时间均与大多数经济结果的改善相关。生态结果则好坏参半。国家与公民社会认证及其持续时间与遮荫树结果呈正相关，但行业VSS未观察到类似关联。对于两类方案，我们均未发现与动物多样性结果呈正相关。研究结果强调，VSS应被理解为一个长期过程，可持续性改善在其中逐步实现。它们还指出VSS在实现环境目标方面的当前局限，尤其是在行业VSS下。更广泛地说，我们的发现强调在评估VSS有效性时考虑时间动态和多重可持续性维度的重要性。