  In this work we consider selling items using a sequential first price auction
mechanism. We generalize the assumption of conservative bidding to extensive
form games (henceforth optimistic conservative bidding), and show that for both
linear and unit demand valuations, the only pure subgame perfect equilibrium
where buyers are bidding in an optimistic conservative manner is the minimal
Walrasian equilibrium.
  In addition, we show examples where without the requirement of conservative
bidding, subgame perfect equilibria can admit a variety of unlikely
predictions, including high price of anarchy and low revenue in markets
composed of additive bidders, equilibria which elicit all the surplus as
revenue, and more. We also show that the order in which the items are sold can
influence the outcome.
