中文摘要
在选择市场中，服务消费者的成本具有异质性且不可契约化，非价格产品特征使企业能够将有利可图与无利可图的消费者区分开来。这种“按质量分选”的一个例子是利用首付来劝退不太可能还款的借款人。我们研究了一个模型，其中消费者具有多维类型，企业提供单一且质量内生的产品，如Spence（1975）所示。这两个要素在企业关于质量的一阶条件中产生了一种新颖的分选激励，该激励是一个简单的比率。分母为边际消费者剩余，是对市场势力的衡量。分子为边际消费者中对质量的边际支付意愿与企业成本之间的协方差。我们提供了使该项符号为正或负的条件，并对比了利润最大化者与社会规划者的分选激励。随后，我们运用这一刻画，在次级汽车贷款中实证量化了分选的重要性，在附加定价模型中解析地确定了其影响的符号，并在健康保险市场中校准了最优竞争政策。
Abstract
Abstract In selection markets, where the cost of serving consumers is heterogeneous and noncontractible, nonprice product features allow a firm to sort profitable from unprofitable consumers. An example of this “sorting by quality” is the use of down payments to dissuade borrowers who are unlikely to repay. We study a model in which consumers have multidimensional types and a firm offers a single product of endogenous quality, as in Spence (1975) . These two ingredients generate a novel sorting incentive in a firm’s first-order condition for quality, which is a simple ratio. The denominator is marginal consumer surplus, a measure of market power. The numerator is the covariance, among marginal consumers, between marginal willingness to pay for quality and cost to the firm. We provide conditions under which this term is signed and contrast the sorting incentives of a profit-maximizer and a social planner. We then use this characterization to quantify the importance of sorting empirically in subprime auto lending, analytically sign its impact in a model of add-on pricing, and calibrate optimal competition policy in health insurance markets.