We briefly survey several insights about value and revenue maximization in multi-object auctions and apply them to the German (and Austrian) UMTS auction. In particular, we discuss in detail the exposure problem that caused firms in Germany to pay almost Euro 20 billion for nothing.

We investigate whether patents that are jointly held by legally independent companies help sustain product-market collusion. We use a simple model of repeated interactions to show that joint patents can serve collusive purposes. Our model generates two testable predictions: when joint patents...