Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We study efficiency properties of the irrevocable exit English auction in a setting with interdependent values. Maskin (1992) [1] shows that the pairwise single-crossing condition is sufficient for efficiency of the English auction with two bidders and suggests that it is also a necessary condition. This paper clarifies and extends Maskin[modifier letter apostrophe]s results to the case of N bidders. We introduce the generalized single-crossing condition--a fairly intuitive extension of the pairwise single-crossing condition--and prove that it is essentially a necessary and sufficient condition for the existence of an efficient equilibrium of the N-bidder English auction.