  Testing the validity of claims made by self-proclaimed experts can be
impossible when testing them in isolation, even with infinite observations at
the disposal of the tester. However, in a multiple expert setting it is
possible to design a contract that only informed experts accept and uninformed
experts reject. The tester can pit competing forecasts of future events against
each other and take advantage of the uncertainty experts have about the other
experts' knowledge. This contract will work even when there is only a single
data point to evaluate.
