A principal must decide whether or not to implement a project which originated with one of her employees. The employees have private information about the quality of the project. A successfully implemented project raises the inventor's chance of promotion, at his peer's expense, but a failed...

We argue that when externalities such as pollution are nonexcludable, agents must be compelled to participate in a "mechanism" to ensure a Pareto-efficient outcome. We survey some of the main findings of the mechanism-design (implementation-theory) literature -- such as the Nash implementation...