Schools of economic thought in the context of "Greco-Roman"

A school of thought, or intellectual tradition, is the perspective of a group of people who share common characteristics of opinion or outlook of a philosophy, discipline, belief, social movement, economics, cultural movement, or art movement.

John Maynard Keynes, 1st Baron Keynes CB, FBA (/keɪnz/ KAYNZ; 5 June 1883 – 21 April 1946), was an English economist whose ideas fundamentally changed the theory and practice of macroeconomics and the economic policies of governments. Originally trained in mathematics, he built on and greatly refined earlier work on the causes of business cycles. One of the most influential economists of the 20th century, he produced writings that are the basis for the school of thought known as Keynesian economics, and its various offshoots. His ideas, reformulated as New Keynesianism, are fundamental to mainstream macroeconomics. He is known as the "father of macroeconomics".

Keynes was educated at King's College at the University of Cambridge, where he graduated in 1904 with a B.A. in mathematics. During the Great Depression of the 1930s, Keynes spearheaded a revolution in economic thinking, challenging the ideas of neoclassical economics that held that free markets would, in the short to medium term, automatically provide full employment, as long as workers were flexible in their wage demands. He argued that aggregate demand (total spending in the economy) determined the overall level of economic activity, and that inadequate aggregate demand could lead to prolonged periods of high unemployment, and since wages and labour costs are rigid downwards the economy will not automatically rebound to full employment. Keynes advocated the use of fiscal and monetary policies to mitigate the adverse effects of economic recessions and depressions. After the 1929 crisis, Keynes also turned away from a fundamental pillar of neoclassical economics: free trade. He criticized Ricardian comparative advantage theory (the foundation of free trade), considering the theory's initial assumptions unrealistic, and became definitively protectionist. He detailed these ideas in his magnum opus, The General Theory of Employment, Interest and Money, published in early 1936. By the late 1930s, leading Western economies had begun adopting Keynes's policy recommendations. Almost all capitalist governments had done so by the end of the two decades following Keynes's death in 1946. As a leader of the British delegation, Keynes participated in the design of the international economic institutions established after the end of World War II but was overruled by the American delegation on several aspects.

Socialist economics comprises the economic theories, practices and norms of hypothetical and existing socialist economic systems. A socialist economic system is characterized by social ownership and operation of the means of production that may take the form of autonomous cooperatives or direct public ownership wherein production is carried out directly for use rather than for profit. Socialist systems that utilize markets for allocating capital goods and factors of production among economic units are designated market socialism. When planning is utilized, the economic system is designated as a socialist planned economy. Non-market forms of socialism usually include a system of accounting based on calculation-in-kind to value resources and goods.

Socialist economics has been associated with different schools of economic thought. Marxian economics provided a foundation for socialism based on analysis of capitalism while neoclassical economics and evolutionary economics provided comprehensive models of socialism. During the 20th century, proposals and models for both socialist planned and market economies were based heavily on neoclassical economics or a synthesis of neoclassical economics with Marxian or institutional economics.

Milton Friedman (/ˈfriːdmən/ ; July 31, 1912 – November 16, 2006) was an American economist and statistician who received the 1976 Nobel Memorial Prize in Economic Sciences for his research on consumption analysis, monetary history and theory and the complexity of stabilization policy. With George Stigler, Friedman was among the intellectual leaders of the Chicago school of economics, a neoclassical school of economic thought associated with the faculty at the University of Chicago that rejected Keynesianism in favor of monetarism before shifting their focus to new classical macroeconomics in the mid-1970s. Several students, young professors and academics who were recruited or mentored by Friedman at Chicago went on to become leading economists, including Gary Becker (Nobel Prize 1992), Robert Fogel (Nobel Prize 1993), and Robert Lucas Jr. (Nobel Prize 1995).

Friedman's challenges to what he called "naive Keynesian theory" began with his interpretation of consumption, which tracks how consumers spend. He introduced a theory which would later become part of mainstream economics and he was among the first to propagate the theory of consumption smoothing. During the 1960s, he became the main advocate opposing both Marxist and Keynesian government and economic policies, and described his approach (along with mainstream economics) as using "Keynesian language and apparatus" yet rejecting its initial conclusions. He theorized that there existed a natural rate of unemployment and argued that unemployment below this rate would cause inflation to accelerate. He argued that the Phillips curve was in the long run vertical at the "natural rate" and predicted what would come to be known as stagflation. Friedman promoted a macroeconomic viewpoint known as monetarism and argued that a steady, small expansion of the money supply was the preferred policy, as compared to rapid and unexpected changes. His ideas concerning monetary policy, taxation, privatization, and deregulation influenced government policies, especially during the 1980s. His monetary theory influenced the Federal Reserve's monetary policy in response to the 2008 financial crisis.

Mainstream economics is the body of knowledge, theories, and models of economics, as taught by universities worldwide, that are generally accepted by economists as a basis for discussion. Also known as orthodox economics, it can be contrasted to heterodox economics, which encompasses various schools or approaches that are only accepted by a minority of economists.

The economics profession has traditionally been associated with neoclassical economics. However, this association has been challenged by prominent historians of economic thought including David Colander. They argue the current economic mainstream theories, such as game theory, behavioral economics, industrial organization, information economics, and the like, share very little common ground with the initial axioms of neoclassical economics.

The history of economic thought is the study of the philosophies of the different thinkers and theories in the subjects that later became political economy and economics, from the ancient world to the present day.

This field encompasses many disparate schools of economic thought. Ancient Greek writers such as the philosopher Aristotle examined ideas about the art of wealth acquisition, and questioned whether property is best left in private or public hands. In the Middle Ages, Thomas Aquinas argued that it was a moral obligation of businesses to sell goods at a just price.

The Chicago school of economics is a neoclassical school of economic thought associated with the work of the faculty at the University of Chicago, some of whom have constructed and popularized its principles. Milton Friedman and George Stigler are considered the leading scholars of the Chicago school.

Chicago macroeconomic theory rejected Keynesianism in favor of monetarism until the mid-1970s, when it turned to new classical macroeconomics heavily based on the concept of rational expectations. The freshwater–saltwater distinction is largely antiquated today, as the two traditions have heavily incorporated ideas from each other. Specifically, new Keynesian economics was developed as a response to new classical economics, electing to incorporate the insight of rational expectations without giving up the traditional Keynesian focus on imperfect competition and sticky wages.

Economic history is the study of history using methodological tools from economics or with a special attention to economic phenomena. Research is conducted using a combination of historical methods, statistical methods and the application of economic theory to historical situations and institutions. The field can encompass a wide variety of topics, including equality, finance, technology, labour, and business. It emphasizes historicizing the economy itself, analyzing it as a dynamic entity and attempting to provide insights into the way it is structured and conceived.

Using both quantitative data and qualitative sources, economic historians emphasize understanding the historical context in which major economic events take place. They often focus on the institutional dynamics of systems of production, labor, and capital, as well as the economy's impact on society, culture, and language. Scholars of the discipline may approach their analysis from the perspective of different schools of economic thought, such as mainstream economics, Austrian economics, Marxian economics, the Chicago school of economics, and Keynesian economics.