Abstract: Jump bidding is a prevalent phenomenon in the ascending auctions. It is a concerning problem whether jump bidding can increase the expected revenue of bidders. Considering the two circumstances of single unit and multi-unit auction,the jump bidding equilibrium is respectively solved by the method of game theory. We calculateds the expected revenue of bidder under the jump bidding equilibrium and compares it with that under non-jump bidding.The general condition under which bidders can use the tool to improve their expected revenues is given.

Key words: auction, independent private value, jump bidding, equilibrium, expected revenue