Marginal outcome tests compare the expected effects of a decision on individuals who are of different races but at the same indifference point of the decision-maker. I present a simple formalization of how such tests can detect racial bias, defined as a deviation from accurate statistical...

We study choice over prescription insurance plans by the elderly using government administrative data to evaluate how these choices are made and evolve over time. We find that there is large "foregone savings" from not choosing the lowest cost plan that has grown over time. We develop a...

We study choice over prescription insurance plans by the elderly using government administrative data to evaluate how these choices are made and evolve over time. We find that there is large "foregone savings" from not choosing the lowest cost plan that has grown over time. We develop a...

Demand for insurance can be driven by high risk aversion or high risk. We show how to separately identify risk preferences and risk types using only choices from menus of insurance plans. Our revealed preference approach does not rely on rational expectations, nor does it require access to...

Insurance plan design has important implications for consumer welfare. In this paper, we model insurance design in the Medicare prescription drug coverage market and show that strategic private insurer incentives impose a fiscal externality on the traditional Medicare program. We document that...