At What Quality and What Price?: Eliciting Buyer Preferences as a Market Design Problem

Abstract

Buyers and sellers in markets often signal to inform the other side about their preferences. Both have a mutual incentive to reveal information with respect to horizontal differentiation, but the case of vertical differentiation is more complex: a buyer claiming they place a high value on quality may attract more sellers of the right ``type'' increasing efficiency, but they might also simply pay a higher price. Although an efficiency-minded social planner may not care about higher prices, if this fear prevents a buyer from stating his of her true preferences, then desirable sorting caused by information-revelation may be unattainable. In this paper, we consider the buyer's vertical differentiation disclosure problem through the lens of a large field experiment conducted in an online labor market. A new signaling mechanism was introduced into the market that allowed buyers to state their relative preferences over price and quality. We find that the buyer signal improved seller-side sorting, with more sellers going to buyers of the right ``type''; the total number of applications also fell. However, sellers also clearly tailored their wages bid to the type of buyer they faced. Despite this markup, buyers chose to honestly disclose their preferences, suggesting they found the sorting effect to dominate the bargaining power effect.