The Causal Impact of Medals on Wine Producers' Prices and the Gains from Participating in Contests
利用葡萄酒交易数据和竞赛记录，通过比较获奖前后的价格差异，估计出奖牌使生产者价格平均提高13%，并发现只有少数竞赛的奖牌能有效反映质量。
The main objective of this article is to estimate the causal effect of wine medals on producers' prices. Our data set combines information on transactions between wine producers and wholesale traders (these data are registered by a wine broker who acts as a middleman in this market), with records from eleven important wine competitions. Our identification strategy exploits a particularity in our data, namely that medals are not only awarded before transaction dates but sometimes also thereafter. Regressing price on dummies indicating past and future medals (plus controls) allows, under weak restrictions, to consistently estimate causal effects of medals by simply calculating differences in the two types of dummy estimates. In addition, the estimates of future medal coefficients can be interpreted as partial correlations between unobserved quality and medal indicators. Our preferred estimate indicates that producers having earned a medal at a competition can increase their price by 13%. The impact for gold is much larger than for silver and bronze, but we cannot reject that the correlation with quality is the same across the three colors. We then calculate expected profits obtained by producers from participating in competitions and find that the incentives to participate are high. Finally, we investigate the efficiency of contests by measuring to what extent attributed awards are good quality indicators: only a minority of competitions attribute medals that are significantly correlated with quality (primarily the ones founded a long time ago, and whose judges are required to evaluate relatively few wines per day).