NBER Publications by Jean Abraham

We develop an empirical method to assess the generosity of employer-sponsored insurance across groups within the U.S. population. A key feature of this method is its simplicity – it only requires data on out-of-pocket (OOP) health care spending and total health care spending and does not require detailed knowledge of health insurance benefit design. We apply our method to assess whether households with a chronically ill member have more or less generous insurance relative to households with no chronically ill members. We find that the chronically ill have less generous insurance coverage than the non-chronically ill. Additional analyses suggest that the reason for this less generous coverage is not that households with a chronically ill member are in different, less generous plans, on av...

This paper illustrates the impact of moral hazard for estimating relative rates of underinsurance and to present an adjustment method to correct for this source of bias. Individuals or households are often classified as underinsured if out-of-pocket spending on medical care relative to income exceeds some threshold. We show that, without adjustment, this common threshold measure of underinsurance will underestimate the number with low levels of insurance coverage due to moral hazard. We propose an adjustment method and apply it to the specific case of estimating the difference in rates of underinsurance among small- versus large-firm workers with full-year, employer-sponsored insurance. Using data from the 2005 Medical Expenditure Panel Survey, we find that after applying the adjustment,...

There has been considerable consolidation in the hospital industry in recent years. Over 900 deals occurred from 1994-2000, and many local markets, even in large urban areas, have been reduced to monopolies, duopolies, or triopolies. This surge in consolidation has led to concern about competition in local markets for hospital services. We examine the effect of market structure on competition in local hospital markets -- specifically, does the hardness of competition increase with the number of firms? We extend the entry model developed by Bresnahan and Reiss to make use of quantity information, and apply it to data on the U.S. hospital industry. In the hospital markets we examine, entry leads to a quick convergence to competitive conduct. Entry reduces variable profits and increases quant...

We examine HMO participation and enrollment in the Medicare risk market for the years 1990 to 1995. We develop a profit- maximization model of HMO behavior, which explicitly considers potential linkages between an HMO's production decision in the commercial enrollee market and its participation and production decisions in the Medicare risk market. Our results suggest that the payment rate is a primary determinant of HMO participation, while the price of a supplemental Medicare insurance policy positively affects HMO Medicare enrollment. We also find empirical support for the existence of complementarities in the joint production of an HMO's commercial and Medicare products.