A competition authority has an objective, which specifies what output profile firms need to produce as a function of production costs. These costs change over time and are only known by the firms. The objective is implementable if inequilibrium, the firms cannot collude on their reports to the...

This paper provides a different approach to establish the uniqueness of equilibrium in Tullock con- tests between two players with asymmetric valuations, when the discriminatory power r is between 1 and 2. Our result complements that of Ewerhart (2017) in Ölling up the remaining gap in the...

The symmetric two-player Hirshleifer (1989) contest is shown to admit a unique equilibrium. The support of the equilibrium strategy is finite and includes, in particular, the zero expenditure level. We also establish a lower bound for the cardinality of the support and an upper bound for the...