We analyze adverse selection problems in which a signal that is related to certain
components of the agent's multidimensional type occurs after contracting. These
components represent information that the principal would like to utilize in the
mechanism they implement. We present illustrative examples and provide a charac-
terization of when the principal can achieve complete information utilization in that
the mechanism results in the same outcome as the principal would implement if the-
re were no information asymmetry between the agent and the principle concerning
these components of the agent's type. Using this characterization, we show that, un-
der broad conditions, the principal cannot achieve complete information utilization
with a binary ex-post signal structure. However, there are ex-post signal structures
with a finite number of signal realizations that enable complete information utilization.
In proving these results, we develop techniques concerning multidimensional screening
that are applicable to other problems in mechanism design.