NBER Publications by Michael P. Keane

The response of aggregate labor supply to various changes in the economic environment is central to many economic issues, especially the optimal design of tax policies. This paper surveys recent work that uses structural models and micro data to evaluate the size of this response. Whereas the earlier literature on this issue often concluded that aggregate labor supply elasticities were small, recent work has identified three key reasons that the aggregate elasticity may be quite large. First, earlier estimates abstracted from several key features, including human capital accumulation, leading to estimates that are dramatically negatively biased. Second, failure to understand that aggregate labor supply adjustments can occur along both the hours per worker and employment margins has led e...

We provide strong evidence of advantageous selection in the Medigap insurance market, and analyze its sources. Using Medicare Current Beneficiary Survey (MCBS) data, we find that, conditional on controls for the price of Medigap, medical expenditures for senior citizens with Medigap coverage are, on average, about $4,000 less than for those without. But, if we condition on health, expenditures for seniors on Medigap are about $2,000 more. These two findings can only be reconciled if those with less health expenditure risk are more likely to purchase Medigap, implying advantageous selection. By combining the MCBS and the Health and Retirement Study (HRS), we investigate the sources of this advantageous selection. These include income, education, longevity expectations and financial planing ...