James Hammitt

Harvard University (Center for Risk Analysis)
718 Huntington Avenue
Boston, MA 02115

E-Mail: EmailAddress: hidden: you can email any NBER-related person as first underscore last at nber dot org

NBER Working Papers and Publications

April 2011Valuing Mortality Risk Reductions: Progress and Challenges
with Maureen L. Cropper, Lisa A. Robinson: w16971
The value of mortality risk reduction is an important component of the benefits of environmental policies. In recent years, the number, scope, and quality of valuation studies have increased dramatically. Revealed-preference studies of wage compensation for occupational risks, on which analysts have primarily relied, have benefited from improved data and statistical methods. Stated-preference research has improved methodologically and expanded dramatically. Studies are now available for several health conditions associated with environmental causes and researchers have explored many issues concerning the validity of the estimates. With the growing numbers of both types of studies, several meta-analyses have become available that provide insight into the results of both methods. Challenges ...

Published: Maureen Cropper & James K. Hammitt & Lisa A. Robinson, 2011. "Valuing Mortality Risk Reductions: Progress and Challenges," Annual Review of Resource Economics, Annual Reviews, vol. 3(1), pages 313-336, October. citation courtesy of

January 2007Health Information and Subjective Survival Probability: Evidence from Taiwan
with Jin-Tan Liu, Meng-Wen Tsou: w12864
The effect of new health information on individuals' expectations about their longevity is examined using a Bayesian learning model. Using two-period panel-structured survey data from Taiwan, we find that subjective probabilities of living to age 75 and 85 are significantly smaller for respondents with more abnormal medical test outcomes and for those receiving more extensive advice on health behavior from their physicians. The subjective probability of survival declines with health shocks such as developing heart disease. Using pooled cross-sectional data, we find that males and married persons are more optimistic about their longevity expectations than females and single persons, and that income is strongly correlated with the subjective probability of living to age 75. Consistent with p...

Published: Liu, Jin-Tan, Meng-Wen Tsou and James K. Hammitt. “Health Information and Subjective Survival Probability: Evidence from Taiwan." Journal of Risk Research 10, 2 (2007): 149-175. citation courtesy of

October 2003Effects of Disease Type and Latency on the Value of Mortality Risk
with Jin-Tan Liu: w10012
We evaluate the effects of disease type and latency on willingness to pay (WTP) to reduce environmental risks of chronic, degenerative disease. Using contingent-valuation data collected from approximately 1,200 respondents in Taiwan, we find that WTP declines with latency between exposure to environmental contaminants and manifestation of any resulting disease, at a 1.5 percent annual rate for a 20 year latency period. WTP to reduce the risk of cancer is estimated to be about one-third larger than WTP to reduce risk of a similar chronic, degenerative disease. The value of risk reduction also depends on the affected organ, environmental pathway, or payment mechanism: estimated WTP to reduce the risk of lung disease due to industrial air pollution is twice as large as WTP to reduce the risk ...

Published: Liu, Jin-Tan and James K. Hammitt. “Effects of Disease Type and Latency on the Value of Mortality Risk." Journal of Risk and Uncertainty 28 (2004): 73-95. citation courtesy of

Valuation of the Risk of SARS in Taiwan
with Jin-Tan Liu, Jung-Der Wang, Meng-Wen Tsou: w10011
Two surveys conducted in Taiwan during the spring 2003 SARS epidemic reveal a high degree of concern about the threat posed by SARS to Taiwan and to residents, although respondents believe they are knowledgeable about the risk of SARS and that it is susceptible to individual control. WTP to reduce the risk of infection and death from SARS is elicited using contingent valuation methods. Estimated WTP is high, implying values per statistical life of US$3 to 12 million. While consistent with estimates for high-income countries, these values are substantially larger than previous estimates for Taiwan and may be attributable to the high degree of concern about SARS at the time the data were collected.

Published: Liu, Jin-Tan, James K. Hammitt, Jun-Der Wang, and Meng-Wen Tsou. “Valuation of the Risk of SARS in Taiwan." Health Economics 14, 1 (2005): 83-91. citation courtesy of

NBER Videos

National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138; 617-868-3900; email:

Contact Us