We analyze Stackelberg leadership in a first-price auction. Leadership is induced by an information system, represented by a spy, that leaks one bidder’s bid before others choose their bids. However, the leader may secretly revise his bid with some probability; therefore, the leaked bid is...

We reconsider the decomposition of the comparative statics effect of a factor price increase on (unconditional) factor demand into a substitution and a size (or level) effect. While for the own price effect the substitution effect and the size effect go into the same negative direction, the...