Relationships on the Rocks: Contract Evolution in a Market for Ice
研究冰块市场中，当上游垄断供应商供应短缺时，零售商优先向忠诚买家供货；上游竞争加剧后，零售商通过扩大贸易信贷来阻止新进入者，同时下游生产率和消费者价格也受到影响。
Firms use relational contracts to support repeated trade. Do these informal agreements evolve in response to market conditions? In a market for ice, firms reestablish relationships on new terms when a prior agreement breaks down. Using transaction data, we show that ice retailers prioritize deliveries to loyal buyers—fishing firms— when supply from the monopolistic manufacturer is scarce. After an upstream shock to competition increases supply, repeated trade lapses, threatening retailers’ positions. Incumbent retailers establish a new agreement expanding trade credit to loyal buyers, which impedes new retailer entry. Upstream competition also increases downstream firms’ productivity and lowers consumer fish prices.