A simple example shows that equilibria can fail to exist in second price (Vickrey) and English auctions when there are both common and private components to bidders' valuations and private information is held on both dimensions. The example shows that equilibrium only exists in the extremes of...

I survey the recent literature on the formation of networks. I provide definitions of network games, a number of examples of models from the literature, and discuss some of what is known about the (in)compatibitily of overall societal welfare with individual incentives to form and sever links.