Surplus extraction on arbitrary type spaces

In this paper I study the possibility of full surplus extraction on arbitrary type spaces, with three main results: (i) I characterize full surplus extraction, (ii) I characterize full surplus extraction assuming that the surplus-extracting allocation is implementable, and (iii) I show that virtually full surplus extraction implies full surplus extraction. The characterizing condition in (ii) above is equivalent to McAfee and Reny's (1992a) condition in their restricted environment. Since they only characterized virtually full surplus extraction, it follows that their proposed mechanisms incur a loss relative to the direct mechanisms studied here, with which full surplus extraction is possible.