An imperfectly-informed regulator needs to procure multiple units of some good (e.g., green energy, market liquidity, pollution reduction, land conservation) that can be produced with heterogeneous technologies at various costs. How should she optimally procure these units? Should she run...

We investigate the possibility of enhancing efficiency by awarding premiums to a set of highest bidders in an English auction - in a setting that extends Maskin and Riley (1984, Econometrica 52: 1473-1518) in three aspects: (i) the seller can be risk averse, (ii) the bidders can have...