Abstract
When lenders screen borrowers using a menu, they generate a contractual externality by making the composition of their competitors’ borrowers worse. Using data from the UK mortgage market and a structural model of screening with endogenous menus, this paper quantifies the impact of asymmetric information on equilibrium contracts and welfare. Counterfactual simulations of a social planner problem show that, because of the externality, there is too much screening along the loan-to-value dimension. The deadweight loss, expressed in borrower utility, is equivalent to an interest rate increase of 30 basis points (a 15 percent increase) on all loans.