He is a health economist with research concentrations in the areas of the societal burden of illness and the socioeconomic determinants of health. In the former area, he was the primary author of the most comprehensive study to date on the societal cost of birth defects. He has authored or coauthored several articles evaluating screening programs and other public health interventions, including the proposed U.S. Food and Drug Administration rule to supplement grains with folate in the late 1990s to prevent birth defects. Part of this research has also been devoted to the methodological problems encountered in estimates of the societal burden of illness and in the evaluation of interventions to reduce that