We propose a dynamic auction mechanism for efficiently allocating multiple heterogeneous indivisible goods. These goods can be split into two distinct sets so that items in each set are substitutes but complementary to items in the other set. The seller has a reserve value for each bundle of...

Procurement auctions are widely used to solicit bids for custom items suchas services, construction projects, public infrastructure, and more. Such auctions involve significant risk because the idiosyncratic nature of the purchases means that delivered quality is uncertain. We examine the case...