“Institutional economics focuses on understanding the role of the evolutionary process and the role of institutions in shaping economic behavior. Its original focus lay in Thorstein Veblen’s instinct-oriented dichotomy between technology on the one side and the ‘ceremonial’ sphere of society on the other. Its name and core elements trace back to a 1919 American Economic Review article by Walton H. Hamilton. Institutional economics emphasizes a broader study of institutions and views markets as a result of the complex interaction of these various institutions (e.g. individuals, firms, states, social norms). The earlier tradition continues today as a leading heterodox approach to economics.
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Fundamentally, this traditional institutionalism (and its modern counterpart institutionalist political economy) emphasizes the legal foundations of an economy (see John R. Commons) and the evolutionary, habituated, and volitional processes by which institutions are erected and then changed (see John Dewey, Thorstein Veblen, and Daniel Bromley).
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A significant variant is the new institutional economics from the later 20th century, which integrates later developments of neoclassical economics into the analysis.”