Robin Eric Hahnel (born March 25, 1946) is an American economist and professor emeritus of economics at American University. He was a professor at American University for many years and traveled extensively advising on economic matters all over the world. He is best known for his work on participatory economics with Z Magazine editor Michael Albert. Politically, Hahnel considers himself a product of the New Left and is sympathetic to libertarian socialism. He has been active in many social movements and organizations for forty years, notably as a participant in student movements opposed to the American invasion of South Vietnam, more recently with the Southern Maryland Greens, a local chapter of the Maryland Green Party, and the Green Party of the United States. Hahnel's work in economic theory and analysis is informed by the work of Marx, Keynes, Piero Sraffa, Michał Kalecki, and Joan Robinson, among others. He has served as a visiting professor or economist in Cuba, Peru, and England. Early critiques: Orthodox Marxism and welfare economics Hahnel was an undergraduate at Harvard when he met Albert, who was studying at the Massachusetts Institute of Technology. Over the course of roughly three decades the duo would produce seven books together. Among the early writings was "Marxism and Socialist Theory" an evaluation of Marxist and Marxist–Leninist theory that emphasized what they believed were serious flaws. Albert and Hahnel argued that while those aspects of Marxist theory rejecting the institutions of private property and markets were well-founded, other aspects of Marxist and Marxist–Leninist doctrine, including its economistic bias, dialectical methodology, historical materialism, class concepts, labour theory of value, crises theory and rejection of visionary thinking, and authoritarian values and tendencies, were either partially or wholly flawed; and often constituted obstacles in the struggle for social justice. Subsequently, they produced "Socialism, Today and Tomorrow", which was an analysis of socialism in the Soviet Union, China and Cuba, as well as a sketch of an alternative theoretical framework for socialism. Their technical study of mainstream welfare economics, "A Quiet Revolution in Welfare Economics", was originally published by Princeton, but did not receive wide distribution. The underground interest in the book prompted its being made available on-line. They argued that traditional welfare economic theory was in an intractable crisis. The core approach that competitive markets produce social efficiency was yielding diminishing returns and "has thwarted, rather than facilitated, advances in analyses of the labour