James Hammitt

Professor of Economics and Decision Sciences
Health Policy and Management
Harvard School of Public Health
(617) 432-4343
Home page:

James K. Hammitt, Ph.D., is Professor of Economics and Decision Sciences in the Departments of Health Policy and Management and of Environmental Health and Director of the Harvard Center for Risk Analysis. Professor Hammitt's research focuses on the development and application of quantitative methods - including benefit-cost, decision, and risk analysis - to health and environmental policy. Topics include management of long-term environmental issues with major scientific uncertainties, such as global climate change and stratospheric-ozone depletion, evaluation of ancillary benefits and countervailing risks associated with risk-control measures, and characterization of social preferences over health and environmental risks using revealed-preference, contingent-valuation, and health-utility methods. Dr. Hammitt earned his A.B. and Sc.M. in Applied Mathematics in 1978, his M.P.P., in 1981, and his Ph.D. in Public Policy in 1988, all from Harvard University. He has been appointed Senior Mathematician at the RAND Corporation (Santa Monica, California) and to the Pierre-de-Fermat Chaire d’Éxcellence at the Toulouse School of Economics (France).

Posted on September 15, 2010
Authors: Rice GE, Hammitt JK, Evans JS
Environmental Science and Technology 2010 44(13): 5216-24  PubmedID: 20540573

We developed a probabilistic model to characterize the plausible distribution of health and economic benefits that would accrue to the U.S. population following reduction of methyl mercury (MeHg) exposure. MeHg, a known human developmental neur... (more »)

Posted on December 9, 2010
Authors: Hogan DR, Zaslavsky AM, Hammitt JK, Salomon J
Sexually Transmitted Infections 2010 86(Suppl 2): 84-92  PubmedID: 21106520   DOI: 10.1136/sti.2010.045104

OBJECTIVE: UNAIDS and country analysts use a simple infectious disease model, embedded in the Estimation and Projection Package (EPP), to generate annual updates on the global HIV/AIDS epidemic. Our objective was to develop m... (more »)

Posted on January 3, 2011
Authors: Neumann PJ, Cohen JT, Hammitt JK, Concannon TW, Auerbach HR, Fang C, Kent DM
Health Economics 2010  PubmedID: 211901163

We assessed how much, if anything, people would pay for a laboratory test that predicted their future disease status. A questionnaire was administered via an internet-based survey to a random sample of adult US respondents. Each respondent answ... (more »)

Posted on January 20, 2013
Authors: Robinson LA, Hammitt JK, Ald JE, Krupnick A, Baxter J
Journal of Homeland Security and Emergency Management 2010 7(1)  DOI: 10.2202/1547-7355.1626

Regulations designed to increase homeland security often require balancing large costs against highly uncertain benefits. An important component of these benefits is the reduced risk of fatalities from terrorist attacks. While the risk to an indiv... (more »)

Posted on February 1, 2010
Authors: von Stackelberg Katherine, Hammitt James
Environmental & Resource Economics 2009 43(1): 45-61  PubmedID: 265940000000   ISSN/ISBN: 0924-6460   DOI: 10.1007/s10640-009-9267-7
We report the results of several contingent valuation (CV) surveys to elicit willingness-to-pay values from the general public for risk reductions associated with decreases in exposure to a chemical, PCBs, in the environment. We also develop Quality ... (more »)
Posted on February 1, 2010
Authors: Chou Shin-Yi, Liu Jin-Tan, Hammitt James
Review of Economics of the Household 2006 4(4): 395-421  PubmedID: 23064711   ISSN/ISBN: 15695239   DOI: 10.1007/s11150-006-0014-3

By reducing risk of large out-of-pocket medical expenses, comprehensive social health insurance may reduce households' motivation to engage in precautionary behaviors such as saving, procurement of private insurance, and spousal labor-force partic... (more »)

Posted on February 1, 2010
Jama-Journal of the American Medical Association 2003 290(2): 228-237  PubmedID: 183990000000   ISSN/ISBN: 0098-7484
Context Approximately 2.7 million US individuals are chronically infected with the hepatitis C virus (HCV). As public health campaigns are pursued, a growing number of treatment candidates are likely to have minimal evidence of liver damage. Objectiv... (more »)
Posted on February 1, 2010
Authors: Corso PS, Hammitt JK, Graham JD, Dicker RC, Goldie SJ
Medical Decision Making 2002 22(5): S92-S101  PubmedID: 178170000000   ISSN/ISBN: 0272-989X   DOI: 10.1177/027298902237713
Background, Rising health care costs and limited resources necessitate trade-offs between resources allocated toward prevention and those toward treatment. Information from opinion polls suggests citizens favor spending a higher proportion of all hea... (more »)
Posted on February 1, 2010
American Journal of Epidemiology 2002 156(8): 761-773  PubmedID: 178653000000   ISSN/ISBN: 0002-9262   DOI: 10.1093/aje/kwf100
This study presents a comprehensive epidemiologic model of hepatitis C in the United States. Through empirical calibration of model parameter values, the objectives were to gain insights into uncertain aspects of the natural history of hepatitis C an... (more »)
Posted on February 1, 2010
Value in Health 2002 5(1): 61-62  PubmedID: 177212000000   ISSN/ISBN: 1098-3015
Posted on February 1, 2010
Authors: Weinstein MC, Toy EL, Sandberg EA, Neumann PJ, Evans JS, Kuntz KM, Graham JD, Hammitt JK
Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research 2001 4(5): 348-361  PubmedID: 11705125   ISSN/ISBN: 1098-3015
The role of models to support recommendations on the cost-effective use of medical technologies and pharmaceuticals is controversial. At the heart of the controversy is the degree to which experimental or other empirical evidence should be required p... (more »)
Posted on February 1, 2010
Authors: Bosch JL, Hammitt JK, Weinstein MC, Hunink MGM
Medical Decision Making 1998 18(4): 381-390  PubmedID: 76422700005   ISSN/ISBN: 0272-989X
This study used a single binary-gamble question per health state per respondent to obtain societal preferences for the health states intermittent claudication and major amputation and compare those with Health Utilities Indices obtained from patients... (more »)
James Hammitt
An advanced course that introduces the standard model of decision-making under uncertainty and its conceptual foundations, as well as challenges, alternatives, and methodological issues arising from the application of these techniques to health issues. [Not offered in 2011-2012]

Benefits and Risks of Dietary Fish Consumption

Developing risk-assessment models for risks associated with fish consumption

Discount rates for the long run

Reviewing key issues relating to the discount rate

Methods for Research-Synthesis: A Cross-Disciplinary Approach

A focus on alternative methods for synthesizing information when forecasting the effects of a policy

Preferences for Mortality Risk Reduction Over the Lifecycle

Investigating individuals' preferences for alternative interventions yielding the same increase in life expectancy

Risk, Perception, and Response Conference

Increasing our understanding of the situations in which people are likely to react poorly to evidence of risk

Using Social-Welfare Functions to Evaluate Policies that Reduce Mortality Risk

Investigating alternative approaches to valuing risk reductions

Valuing Reductions in Morbidity Risk: WTP and QALYs

Investigating the relationship between WPT and QALYs and the differences in their theoretical foundations