a b s t r a c t
I propose a simple method to nonparametrically estimate the utility function in first-price, sealed-bid
auctions when bidders’ participation is exogenous. Using a pair of bid densities, each for a different
number of bidders, I establish a contraction mapping that converges to the true utility function. The
method employs nonparametric estimates in place of the true bid densities to construct the contraction
mapping and computes the utility function by iterating the contraction operator. A Monte Carlo study
shows that the method approximates the true utility function and valuation density.