  In their study of price discrimination for a monopolist selling heterogeneous
products to consumers having private information about their own
multidimensional types, Rochet and Chon\'e (1998) discovered a new form of
screening in which consumers with intermediate types are bunched together into
isochoice groups of various dimensions incentivized to purchase the same
product. They analyzed a particular example involving customer types
distributed uniformly over the unit square. For this example, we prove that
their proposed solution is not selfconsistent, and we indicate how consistency
can be restored.
