In dynamic models driven by diffusion processes, the smoothness of the value function plays a crucial role for characterizing properties of the solution. However, available methods to ensure such smoothness have limited applicability in economics, and economists have often relied on either...

I study the optimal choice of investment projects in a continuous time moral hazard model with multitasking. While in the first best, projects are invariably chosen by the net present value (NPV) criterion, moral hazard introduces a cutoff for project selection which depends on both a...

We prove that under standard Lipschitz and growth conditions, the value function of all optimal control problems for one-dimensional diffusions is twice continuously differentiable, as long as the control space is compact and the volatility is uniformly bounded below, away from zero. Under...

I study the optimal choice of investment projects in a continuous-time moral hazard model with multitasking. While in the first best, projects are invariably chosen by the net present value (NPV) criterion, moral hazard introduces a cutoff for project selection which depends on both a project's...

This paper considers a model of reference-dependent utility in which the individual makes a conscious choice of her reference point for future consumption. The model incorporates the combination of loss aversion and anticipatory utility as competing forces in the determination of the optimal...

The standard framework for analyzing games with incomplete information models players as if they form beliefs about their opponents' beliefs about their opponents' beliefs and so on, that is, as if players have an infinite depth of reasoning. This strong assumption has nontrivial implications,...

We propose to strengthen Popper's notion of falsifiability by adding the requirement that when an observation is inconsistent with a theory, there must be a "short proof" of this inconsistency. We model the concept of a short proof using tools from computational complexity, and provide some...