Summary: CS 6100 Homework 4
Note, these exercises may be done in groups of one, two, or three. If more than one person is involved, list all the names
on ONE set of answers. Groups may change throughout the term. Working in groups is a BIG plus for you. Take
advantage of it. If you work in groups, you must work in the group for the ENTIRE assignment. It is considered cheating if
you work with someone else for some of the answers, but turn in an individual copy of the answers. It is an all or nothing
situation. You can't work together on some questions and alone on some. Sometimes I see an individual whose name is
listed in two groups. This is strictly forbidden and is considered cheating. You cannot work in two groups.
1. Discuss how the revelation principle relates the Vickrey auction to the English auction.
2. Show an example where an agent is best off bidding insincerely if a Vickrey auction is implemented as
"open cry" instead of sealed bid.
3. Multi-unit auctions. There are m identical items to be auctioned off to n players. Each player is single-
minded (wants only the bundle specified) and wants qi items at a total value vi (more than qi items give
the same value). Since the bidders are single-minded, the bids are of the form (pi, bi) where pi is an
integer in 1. .m that indicates the number of items of interest and bi is the bid for them (assume bi are
Example: There are 50 identical items. The bids are as follows: