Jeffrey D. Sachs is a University Professor and Director of the Center for Sustainable Development at Columbia University. He is President of the UN Sustainable Development Solutions Network and a commissioner of the UN Broadband Commission for Development. Sachs has been advisor to three United Nations Secretaries-General, and currently serves as an SDG Advocate under Secretary-General António Guterres. Sachs was twice named among Time magazine's 100 most influential world leaders and was ranked by The Economist among the top three most influential living economists.