Exercise 5 -- Three Problems


Please hand in hard copy.
You may discuss these problems with classmates, but your work must be your own.
Reference all sources.

1. Consider the pairwise second-price tournament, the first two tournaments we ran in class. Define the criterion

E[Δ12] = E[surplus of 1 if 1 wins - surplus of 2 if 2 wins]

That is, the expected difference in surplus between bidder 1 and bidder 2. Show that if we use Δ12 as the criterion, the resultant equilibrium bidding function is a dominant strategy (can't be beat!).

2. [At least if you do this the way I did it, it's a little tricky. Hint: the answer is linear in v but may not look it.]
Find the equilibrium (and hence dominant strategy) in the pairwise second-price tournament using the criterion described above when valuations are distributed uniformly on [0,1].

3. Repeat question 2 for general value distribution F. Simplify the answer as much as you can. It will, however, involve at least one integral that must be left in general form.

4. [Extra Credit and hard]
Consider the Average-of-Other-Bids (AVO) auction, as described in assignment 3, questions 1 and 2. Is there a value distribution F for which there is no equilibrium? If there is, give an example; if there is not, prove it.