Simultaneous Ascending Bid Auctions

We analyze simultaneous ascending bid auctions with multiple objects in which bidders can be budget constrained. The presence of budget constraints shrinks the equilibrium set. A family of equilibria with a high degree of competition, as well as a family of equilibria with a high degree of collusion, disappear. When the budget available to each bidder is private information then even a very small probability of having a budget constrained bidder may have a strong impact on th eequilibrium set, eliminating the most competitive equilibria. JEL classification number: D44