James Hammitt - Academia.edu (original) (raw)

Papers by James Hammitt

Journal of Agricultural Economics, Mar 10, 2015

Journal of Virus Eradication, 2019

The Japanese Economic Review, 2019

Journal of Risk and Uncertainty, 2018

European Journal of Risk Regulation, 2013

Journal of Benefit-Cost Analysis, 2017

Regulatory impact analyses (RIAs) weigh the benefits of regulations against the burdens they impo... more Regulatory impact analyses (RIAs) weigh the benefits of regulations against the burdens they impose and are invaluable tools for informing decision makers. We offer 10 tips for nonspecialist policymakers and interested stakeholders who will be reading RIAs as consumers.1.Core problem: Determine whether the RIA identifies the core problem (compelling public need) the regulation is intended to address.2.Alternatives: Look for an objective, policy-neutral evaluation of the relative merits of reasonable alternatives.3.Baseline: Check whether the RIA presents a reasonable “counterfactual” against which benefits and costs are measured.4.Increments: Evaluate whether totals and averages obscure relevant distinctions and trade-offs.5.Uncertainty: Recognize that all estimates involve uncertainty, and ask what effect key assumptions, data, and models have on those estimates.6.Transparency: Look for transparency and objectivity of analytical inputs.7.Benefits: Examine how projected benefits rel...

Digestive Diseases and Sciences, Sep 1, 2002

Duke Environmental Law Policy Forum, 1997

Environmental Science & Technology, 2016

Sexually transmitted infections, 2012

Population-based HIV testing surveys have become central to deriving estimates of national HIV pr... more Population-based HIV testing surveys have become central to deriving estimates of national HIV prevalence in sub-Saharan Africa. However, limited participation in these surveys can lead to selection bias. We control for selection bias in national HIV prevalence estimates using a novel approach, which unlike conventional imputation can account for selection on unobserved factors. For 12 Demographic and Health Surveys conducted from 2001 to 2009 (N=138 300), we predict HIV status among those missing a valid HIV test with Heckman-type selection models, which allow for correlation between infection status and participation in survey HIV testing. We compare these estimates with conventional ones and introduce a simulation procedure that incorporates regression model parameter uncertainty into confidence intervals. Selection model point estimates of national HIV prevalence were greater than unadjusted estimates for 10 of 12 surveys for men and 11 of 12 surveys for women, and were also gre...

Summary of Argument: Throughout this proceeding, EPA has identified no policy or normative criter... more Summary of Argument: Throughout this proceeding, EPA has identified no policy or normative criteria to justify its NAAQS standards, thus suggesting that science alone can be used to determine the appropriate air quality standard. Science plays a critical, indeed essential, role in evaluating the risks of possible air quality standards being considered for adoption by EPA. However, science by itself

Risk Analysis, 2012

Expert judgment (or expert elicitation) is a formal process for eliciting judgments from subject‐... more Expert judgment (or expert elicitation) is a formal process for eliciting judgments from subject‐matter experts about the value of a decision‐relevant quantity. Judgments in the form of subjective probability distributions are obtained from several experts, raising the question how best to combine information from multiple experts. A number of algorithmic approaches have been proposed, of which the most commonly employed is the equal‐weight combination (the average of the experts’ distributions). We evaluate the properties of five combination methods (equal‐weight, best‐expert, performance, frequentist, and copula) using simulated expert‐judgment data for which we know the process generating the experts’ distributions. We examine cases in which two well‐calibrated experts are of equal or unequal quality and their judgments are independent, positively or negatively dependent. In this setting, the copula, frequentist, and best‐expert approaches perform better and the equal‐weight comb...

Risk Analysis, 2013

Predicting the human‐health effects of reducing atmospheric emissions of nitrogen oxide (NOx) emi... more Predicting the human‐health effects of reducing atmospheric emissions of nitrogen oxide (NOx) emissions from power plants, motor vehicles, and other sources is complex because of nonlinearity in the relevant atmospheric processes. We estimate the health impacts of changes in fine particulate matter (PM2.5) and ozone concentrations that result from control of NOx emissions alone and in conjunction with other pollutants in and outside the mega‐city of Shanghai, China. The Community Multiscale Air Quality (CMAQ) Modeling System is applied to model the effects on atmospheric concentrations of emissions from different economic sectors and geographic locations. Health impacts are quantified by combining concentration‐response functions from the epidemiological literature with pollutant concentration and population distributions. We find that the health benefits per ton of emission reduction are more sensitive to the location (i.e., inside vs. outside of Shanghai) than to the sectors that ...

Risk Analysis, 2001

Public risk perceptions and demand for safer food are important factors shaping agricultural prod... more Public risk perceptions and demand for safer food are important factors shaping agricultural production practices in the United States. Despite documented food safety concerns, little attempt has been made to elicit consumers' subjective risk judgments for a range of food safety hazards or to identify factors most predictive of perceived food safety risks. In this study, over 700 conventional and organic fresh produce buyers in the Boston area were surveyed for their perceived food safety risks. Survey results showed that consumers perceived relatively high risks associated with the consumption and production of conventionally grown produce compared with other public health hazards. For example, conventional and organic food buyers estimated the median annual fatality rate due to pesticide residues on conventionally grown food to be about 50 per million and 200 per million, respectively, which is similar in magnitude to the annual mortality risk from motor vehicle accidents in t...

Review of Economics of the Household, 2006