This paper presents an axiomatic characterization of a family of solutions to two-player quasi-linear social choice problems. In these problems the players select a single action from a set available to them. They may also transfer money between themselves. The solutions form a one-parameter...

The basic form of economic exchange is a bilateral relationship between buyer and seller. If economic conditions are common knowledge there is no problem in principle to determine the efficient quantity to trade. But if benefits are known only to the buyer and costs are known only to the seller...