Each of this dissertations chapters studies a different problem in microeconomics. The approach used in each is uniquely tailored to deal with a particular problem.The first chapter shows how to optimally delegate actions to an informed agent when the principal cannot require payments. Instead, they are able to commit to actions in the future that affect both parties’ payoffs. I use these results to study a model of delegating decisions sequentially, and a model of delegation in which the principal can use measures that are costly to both parties. I characterize optimal mechanisms in both of these settings and show how the mechanisms vary with the model’s parameters.The second chapter compares the predictive performance of several models of...