We estimate the sensitivity of Internet retail purchasing to sales taxes using eBay data. Our first approach exploits the fact that a seller's location?and therefore the applicable tax rate?is revealed only after a buyer has expressed interest in an item. We document how adverse tax "surprises"...

We document some early effects of how mobile devices might change Internet and retail commerce. We present three main findings based on an analysis of eBay's mobile shopping application and core Internet platform. First, early adopters of mobile e-commerce applications appear to be people who...

We present new evidence on consumer liquidity constraints and the credit market conditions that might give rise to them. We analyze unique data from a large auto sales company serving the subprime market. Short-term liquidity appears to be a key driver of consumer behavior. Demand increases...

Standard incentive theory models provide a rich framework for studying informational problems but assume that contracts can be perfectly enforced. This paper studies the design of self-enforced relational contracts. I show that optimal contracts often can take a simple stationary form, but that...

Early admissions are widely used by selective colleges and universities. We identify some basic facts about early admissions policies, including the admissions advantage enjoyed by early applicants and patterns in application behavior, and propose a game-theoretic model that matches these facts....

Premiums in health insurance markets frequently do not reflect individual differences in costs, either because consumers have private information or because prices are not risk rated. This creates inefficiencies when consumers self-select into plans. We develop a simple econometric model to...

We develop a model in which firms set impersonal salary levels before matching with workers. Wages fall relative to any competitive equilibrium while profits rise almost as much, implying little inefficiency. Furthermore, the best firms gain the most from the system while wages become...

We use employee-level panel data from a single firm to explore the possibility that individuals may select insurance coverage in part based on their anticipated behavioral ("moral hazard") response to insurance, a phenomenon we label "selection on moral hazard." Using a model of plan choice and...

We analyze the extent to which individuals' choices over five employer-provided insurance coverage decisions and one 401(k) investment decision exhibit systematic patterns, as would be implied by a general utility component of risk preferences. We provide evidence consistent with an important...