In this thesis, I study mechanism design problems in environments where the information necessary to make decisions is affected by the actions of principal or agents. The first chapter considers the problem of a principal who must allocate a good among a finite number of agents, each of whom values the good. Each agent has private information about the principal\u27s payoff if he receives the good. There are no monetary transfers. The principal can inspect agents\u27 reports at a cost and punish them, but punishments are limited because verification is imperfect or information arrives only after the good has been allocated for a while. I characterize an optimal mechanism featuring two thresholds. Agents whose values are below the lower thre...