Product Design in Selection Markets

42 Pages Posted: 30 Sep 2011 Last revised: 5 Nov 2015

See all articles by Andre Veiga

Andre Veiga

Imperial College London

E. Glen Weyl

Microsoft Research New York City; RadicalxChange Foundation

Date Written: November 4, 2015


In selection markets, where the cost of serving consumers is heterogeneous and noncontractible, non-price product features allow a firm to sort profitable from unprofitable consumers. An example of this “sorting by quality” is the use of downpayments to dissuade borrowers 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.

Keywords: selection markets, cream-skimming, insurance markets, add-on pricing, subprime lending, product design

JEL Classification: D41, D42, D43, D86, G21, I13

Suggested Citation

Veiga, Andre and Weyl, Eric Glen, Product Design in Selection Markets (November 4, 2015). Quarterly Journal of Economics, Forthcoming. Available at SSRN: or

Andre Veiga

Imperial College London ( email )

South Kensington Campus
Exhibition Road
London, Greater London SW7 2AZ
United Kingdom

Eric Glen Weyl (Contact Author)

Microsoft Research New York City ( email )

641 Avenue of the Americas
7th Floor
New York, NY 10011
United States
8579984513 (Phone)


RadicalxChange Foundation ( email )


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