My research agenda aims to understand the constraints that vulnerable populations face in making decisions that affect their health status, and in particular the effects of government policies designed to benefit these populations. In practice, this has meant my research focuses on several distinct areas related to the health economics of vulnerable populations.

I plan on adding links to my papers on this page at some point in the near future.


I am interested in understanding the effects of Medicare on vulnerable populations, as well the future of Medicare in a changing health care technology environment.

  1. I am closely involved as an investigator in a research project funded by the Center for Medicare and Medicaid Services (formerly the Health Care Financing Administration), which aims to forecast the effects of changes in technology on future Medicare expenditures. For this project, we assembled a distinguished panels of experts in biology, various branches of medicine, and health economics. We challenged these panels to make their best assessments that each item in a detailed list of promising medical technologies would come into widespread use-and to provide some measure of the uncertainty in their predictions. My main role in this project has been in developing and implementing a state-of-the-art demographic model that allows projections of future Medicare expenditures. This model takes into account the changing demographics of life span and disease, and most importantly, introduces the expert predictions on technological change-resulting ultimately in improved forecasts of future Medicare expenditures.
  2. In a related project, newly funded by an R03 grant from the National Institute on Aging (NIA), I (along with two RAND researchers) am examining the redistributive consequences of Medicare and its financing. While it is well known that Medicare induces an intergenerational transfer from younger people to older people (mainly because medical care expenditures by the elderly grow faster than inflation each year and the "pay-as-you-go" structure of Medicare financing), it is not clear what intra-generational transfers Medicare induces. While the poor pay less in Medicare taxes, they also spend less on medical care when older and survive for a shorter time than the rich. This project is designed to determine whether Medicare, on net, induces a transfer from rich to the poor within a generation.
  1. There is a long established line of research papers demonstrating decreasing rates of disability among elderly populations in the developed world over the past two decades. In recent research, my colleagues and I have shown that the same cannot be said for younger populations. The rate of severely limiting disabilities has been increasing in the last decade for these populations.
  2. I am the Principal Investigator for a new grant from the Stanford Center for the Study of Demography and the Economics of Health and Aging (CDEHA) designed to explain these trends. I am examining two competing explanations for increasing disability: changes in the health of these populations (increasing rates of diabetes, obesity, asthma, and so on) and changes in the economic incentives to report disability.
  3. In related research, I am an investigator on a grant from the Robert Woods Johnson Foundation that evaluates the importance of Medicare in explaining trends in public disability insurance application rates.
  4. I am also working with a group from RAND and UC Berkeley on a contract with the California Department of Industrial Relations to evaluate the equity of the California Permanent Disability Schedule for workers' compensation insurance. We have an article forthcoming in the American Journal of Industrial Medicine on the topic.

I am a lead investigator on a research project aimed at evaluating threats to adequate nutrition among the poor in America. These projects are funded by the US Department of Agriculture and by Northwestern University and University of Chicago's Joint Center for Poverty Research.

  1. The first paper in this project, forthcoming at the American Journal of Public Health, finds evidence in nationally representative data that poor American families respond to unusually cold weather shocks by increasing expenditures on fuel, while decreasing expenditures on food. This is confirmed by other data sources, which indicate poor families consume fewer calories in winter relative to the rest of the year.
  2. The second paper in this research agenda, submitted to the Journal of Human Resources aims at evaluating a popular method in survey research of assessing the availability of food, and the presence of hunger among the poor in America. Questions on "food security" are prominently featured in large government surveys of the American population, and are used to measure the presence of hunger. This second paper examines how well the answers to food security questions correlate with serum measures of nutritional adequacy and caloric intake. For elderly, food insecurity is a good measure of nutritional adequacy, but it does not perform as well for children.
  3. The final paper in this research arc, which is currently being revised, evaluates the success of the school breakfast program in providing adequate nutrition to its enrollees. The idea behind the paper is to compare nutritional outcomes for kids in summer, when school breakfasts are not offered, against outcomes during the school year.
Economics of HIV
  1. I am the co-PI on an R01 grant funded by the Agency for Health Care Research and Quality that aims at exploring the links between employment, insurance coverage, and the health of HIV patients. One aim of this project is to evaluate the most effective ways to shape the public provision of insurance for HIV patients-especially in light of new and effective pharmaceutical products which slow the course of HIV disease.
  2. In a related research arc, I am the head of the only research team exploring the economics of the viatical settlements market, a secondary market for life insurance that can be a key financial resource for HIV patients. While the R03 grant from the National Institute on Aging to study this market has recently lapsed, it was quite productive. In particular,
Uninsured Populations

I am a PI on a recently funded grant from the Robert Woods Johnson foundation that aims to explore the dynamics of uninsurance among the employed. While there is much research on uninsured populations, this grant focuses on a subpopulation of uninsured that has received little attention-the employed uninsured. For most in this subpopulation, there is no government program that provides insurance, and hence it is important to understand who this population consists of, why the size of this population has been rising in recent years, and how long people tend to remain in this subpopulation.

Economics of Alcohol and Smoking

  1. I am the PI on a grant from the National Institute on Alcoholism and Alcohol Abuse aimed at estimating the demand curve for alcohol treatment services in the context managed care insurance. High deductibles, low stop-losses, and strict lifetime limits make the extensive use of these services rare. This grant is in its final year.
  2. I (along with a RAND researcher) have started a research project on the optimal taxation on cigarettes when people are myopic. This research asks whether it is possible at all to calculate an optimal tax to discourage smoking when people behave irrationally.
Other Topics in Health Economics
  1. William Vogt and I have submitted a paper to the Journal of Law and Economics that proposes a new explanation for the odd fact that prices of branded pharmaceutical products rise after patent expiry and generic entry, when conventional model of competition would predict price declines. The key to the explanation lies in understanding the pharmaceutical firm's demand management problem.
  2. A paper from my dissertation on the returns to specialization in medicine is under review at the Review of Economics and Statistics.
  3. I (along with Neeraj Sood and Michael Schoenbaum) have published a paper in Economics Letters that outlines a strategy of calculating optimal contributions to flexible spending accounts. My colleagues and I have applied for a patent for this technique.
  4. Finally, I have recently published a paper in Medical Care on the health insurance choices of managed care experts. We find that high income experts are less likely than similar, non-expert controls to pick HMO-style plans.
Other Topics in Economics, Econometrics, and Medicine

I do work on a number of other topics in economics, econometrics, and medicine, including the treatment for head and neck cancer, the mortality effects of Swan-Ganz catheters, on overtime regulation in California, and two projects on econometric topics: probit models with endogenous regressors and random choice logit models. While these do not fit nicely into my "theme" area of vulnerable populations, one has to have fun somehow!