We discuss the regulation of a multiproduct monopolist when the firm has private information about cost or demand conditions. The regulator offers the firm a set of prices from which to choose. When there is private information only about costs, the firm should always have a degree of discretion...

We model firms as supplying utility directly to consumers. The equilibrium outcome of competition in utility space depends on the relationship pi(u) between profit and average utility per consumer. Public policy constraints on the "deals" firms may offer affect equilibrium outcomes via their...