中文摘要
消费者剩余，即需求曲线与价格之间的面积，在许多贸易与增长模型中发挥着关键作用。对其进行量化通常需要估计并外推需求曲线。本文通过将企业视为投入品的消费者，提供了一种衡量消费者剩余的替代方法。我们表明，下游企业边际成本对供应商增加与减少的弹性，衡量了下游企业的消费者剩余相对于其投入成本的大小。使用比利时数据并对供应商可及性的变化进行工具变量处理，我们发现，供应商每增加或减少1%，下游企业的边际成本大约下降或上升0.3%。我们的估计直接为多样性偏好效应的强度以及沿质量阶梯移动所带来的收益提供了信息。我们利用消费者剩余的微观经济估计，在增长核算框架中评估了供应商增加与减少的宏观经济重要性。我们发现，供应商流动可能解释了约一半的总体生产率增长。
Abstract
Consumer surplus, the area between the demand curve and the price, plays a key role in many models of trade and growth. Quantifying it typically requires estimating and extrapolating demand curves. This paper provides an alternative approach to measuring consumer surplus by focusing on firms as consumers of inputs. We show that the elasticity of a downstream firm's marginal cost to supplier additions and separations measures the downstream firm's consumer surplus relative to its input costs. Using Belgian data and instrumenting for changes in supplier access, we find that for every 1% of suppliers gained or lost, the marginal cost of downstream firms falls or rises by roughly 0.3%. Our estimates are directly informative about the strength of love‐of‐variety effects and the gains from movements along quality ladders. We use our microeconomic estimates of consumer surplus to assess the macroeconomic importance of supplier additions and separations in a growth accounting framework. We find that supplier churn plausibly accounts for about half of aggregate productivity growth.