I am a Professor of Economics at Columbia Business School. My main academic interests are in economic theory and environmental economics. I am also actively involved with environmental organizations, being on the board of directors of the Union of Concerned Scientists, Chair of the Board of the Coalition for Rainforest Nations and on the Advisory Board of the Environmental Defense Fund. Photography, particularly nature photography, and birdwatching have been lifelong hobbies.

I teach courses on advanced microeconomic theory, current developments in energy markets, the impact of climate change on business and economic aspects of corporate social responsibility.

My recent books include Endangered Economies: Why the Neglect of Nature Threatens Our Prosperity, When Principles Pay: Corporate Social Responsibility and the Bottom Line, Nature and the Marketplace, and Valuing the Future: Economic Theory and Sustainability.

I’m a member of the National Academy of Sciences, a Fellow of the Econometric Society and of the Association of Environmental and Resource Economists (of which I am Past President), and recipient of the Association’s prize for a publication of enduring quality. My full CV is here.

I was recently a member of the High Level Commission on Carbon Prices, which produced a report as a follow-up to the Paris 2015 climate meeting on the implementation of carbon prices: the report is here. And before that I was a member of a commission that wrote a report for then-President Sarkozy of France on improving the measurement of economic performance and social progress, which is here.