American Economic Journal: Applied Economics · 2022 · Lorenzo Casaburi、Tristan Reed
中文摘要
随机对照试验中竞争企业间的干扰能够提供关于市场结构的信息。一项对塞拉利昂向农民收购可可的贸易商的随机子集进行补贴的实验阐释了这一思路。通过古诺竞争模型解读从农民处收购的价格和数量上的处理组与对照组差异，揭示出贸易商之间的差异化程度较低。将这一结果与世界价格的准实验变异相结合，表明参与竞争的贸易商数量比在一个村庄中经营的贸易商数量高出50百分点。自身价格和交叉价格供给弹性很高。在这一价值链的第一阶段，农民面临的是一个竞争性市场。（JEL L13, L14, O13, Q12, Q13）
Abstract
Interference across competing firms in RCTs can be informative about market structure. An experiment that subsidizes a random subset of traders who buy cocoa from farmers in Sierra Leone illustrates this idea. Interpreting treatment-control differences in prices and quantities purchased from farmers through a model of Cournot competition reveals differentiation between traders is low. Combining this result with quasi-experimental variation in world prices shows that the number of traders competing is 50 percent higher than the number operating in a village. Own-price and cross-price supply elasticities are high. Farmers face a competitive market in this first stage of the value chain. (JEL L13, L14, O13, Q12, Q13)