Pigovian economics

WSJ - Mr. Pigou's intellectual legacy is being rediscovered, and, unlike those of Messrs. Keynes and Friedman, it enjoys bipartisan appeal. Leading Republican-leaning economists such as Greg Mankiw and Gary Becker have joined Democrats such as Paul Krugman and Amartya Sen in recommending a Pigovian approach to policy. Much of President Barack Obama's agenda—financial regulation, cap and trade, health care reform—is an application of Mr. Pigou's principles. Whether the president knows it or not, he is a Pigovian.

Mr. Pigou pioneered the study of market failure—the branch of economics that explores why free enterprise sometimes [fails]. During the 1930s, Mr. Keynes lampooned him as a reactionary because of his suggestion that the economic slump would eventually recover of its own accord.

But while Mr. Pigou believed capitalism works tolerably most of the time, he also demonstrated how, on occasion, it malfunctions. His key insight was that actions in one part of the economy can have unintended consequences in others.

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