I am an interdisciplinary historian, with broad interests in the social, demographic, economic, and environmental history of Europe and the United States. Most of my recent research focuses on the interaction of population, agricultural change, and the environment in the Western U.S., with a special emphasis on agricultural communities in the Great Plains region. Since 1995 I have been part of a team of researchers who have used support from the National Institutes of Health and the National Science Foundation to study the relationship between population and environment in the U.S. Great Plains.

Before joining the University of Colorado Boulder in 2014, I was Assistant Director of the U.S. National Science Foundation (NSF), with responsibility for the Directorate for the Social, Behavioral and Economic Sciences. As NSF Assistant Director I was involved in the formulation and execution of U.S. science policy, especially in areas related to interdisciplinary research and teaching, and in the development of policies that increased access to scientific data and publications.

From 2001 to 2009 I was Director of the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan, where I led efforts to ensure that important social science data are documented and preserved for long-term research access. I also spearheaded a research program on the protection of human research subjects and spoke frequently about economically sustainable long-term preservation of research data.