Elinor Ostrom is the Arthur F. Bentley Professor of Political Science and Co-Director of the Workshop in Political Theory and Policy Analysis, and the Center for the Study of Institutions, Population, and Environmental Change at Indiana University, Bloomington. Her books include Governing the Commons: Rules, Games, and Common-Pool Resources (with Roy Gardner and James Walker); Heterogeneity and Cooperation in Two Domains (with Robert Keohane); Trust and Reciprocity: Interdisciplinary Lessons from Experimental Research (with James Walker); The Commons in the New Millennium: Challenges and Adaptations (with Nives Dolsak), and Foundations of Social Capital (with T. K. Ahn).