The Robustness of Exclusion in Multi-dimensional Screening

We extend Armstrong's result on exclusion in multi-dimensional screening models in two key ways, providing support for the view that this result is generic and applicable to many different markets. First, we relax the strong technical assumptions he imposed on preferences and consumer types. Second, we extend the result beyond the monopolistic market structure to generalized oligopoly settings with entry. We also analyze applications to several quite different settings: credit markets, the automobile industry, research grants, the regulation of a monopolist with unknown demand and cost functions, and involuntary unemployment in the labor market.