International climate negotiations have been troubled by mutual mistrust. At the same time, a hope seems to prevail that once enough countries moved forward, others would follow suit. If the abatement game faced by climate negotiators is a Prisoners' Dilemma, and countries are narrowly...

Individuals with a preference for keeping moral obligations may dislike learning that voluntary contributions are socially valuable: Such information can trigger unpleasant feelings of cognitive dissonance. I show that if initial beliefs about the social value of contributions are sufficiently...

The perfectly competitive market - a hypothetical situation free of market failure - serves as a benchmark for economic theory, providing the basis for the two fundamental welfare theorems. The radical abstractions of this idea makes it hard to grasp its full implications, however. In this...

The perfectly competitive market - a hypothetical situation free of market failure - is the basis for the two fundamental welfare theorems, and an important benchmark for economic theory. The radical abstractions of this idea, however, make its full implications hard to grasp. I address this...

I demonstrate a straightforward but apparently widely unrecognized implication of the standard requirements for perfect competition: an economy in which consumers can choose to learn is generally not perfectly competitive. In particular, if endogenous welfare relevant learning is feasible, the...

Humans are fundamentally social. Social activities require coordination, which may yield multiple equilibria in the form of stable, self-reinforcing patterns of herd behavior. Since environmental impacts can differ substantially between alternative equilibria, such self-reinforcing behaviors...