Buyers' response to third‐party quality certification: Theory and evidence from Ethiopian wheat traders
研究了低收入国家小农农业价值链中交易商采用第三方质量认证的决策，通过理论模型和埃塞俄比亚小麦交易商的实地实验发现，交易商对认证产品的专业化意愿随市场认证份额增加而增强，尤其在更大市场中效果更显著，但对未认证小麦质量变化反应不足。
Abstract When quality attributes of a product are not directly observable, third‐party certification (TPC) enables buyers to distinguish between quality levels and reward sellers accordingly. We study the adoption of TPC by traders in smallholder‐based agricultural value chains in low‐income countries, where traders aggregate products from many small‐scale producers before selling in bulk to downstream processors. In this context, the introduction of TPC services has oftentimes failed. We develop a theoretical model identifying how different market conditions affect traders' choice to purchase certified output from farmers. Next, using a novel lab‐in‐the‐field experiment with Ethiopian wheat traders, we examine the model's predictions. Traders’ willingness to specialize in certified output increases with the share of certified wheat in the market, and this effect is stronger in larger markets. However, we find that traders do not optimally respond to variation in the quality of uncertified wheat in the market. We also analyze conditions where traders deviate from optimal behavior and discuss implications for research and policy making to promote TPC in smallholder‐based value‐chains.