One of the great success stories in economics and game theory during the latter half of the 20th century was the systematic theoretical investigation of incomplete information in different economic environments, including auctions. From an econometrician's perspective, theoretical models of incomplete information are particularly compelling because they provide richer explanations of the observed heterogeneity in data than ones relying on measurement error or productivity shocks. Models of auctions are especially attractive because the rules of an auction govern how the potential buyers must...