The General Theory was criticized and questioned by a few orthodox bourgeois economists in the early stage of publication, and it also caused widespread controversy. However, the basic ideas of the General Theory were quickly accepted by bourgeois economists. Followers of Keynes have interpreted, mended and developed the general theory a lot, and formed the Keynesian school, or Keynesianism, which has a wide influence on theory and policy. After the Second World War, especially in the 1950s and 1960s, Keynesianism occupied a dominant position in western economics and university forums.
Because the total analysis of the general theory is based on the assumption that the skills and quantity of the existing labor force, the quantity and technology of the existing capital equipment, the degree of competition and the social structure remain unchanged, the analysis method it adopts is also called "short-term comparative static analysis". In order to further improve the general theory in theory, Keynes's followers tried to make it "long-term" and "dynamic", put forward various "economic fluctuation theories" and "economic growth theories", and sought ways to make capitalism grow steadily. In this process, Keynesians were divided into two factions because of their different attitudes towards traditional vulgar economics and different concepts and premises used in the analysis. One is neoclassical comprehensive school or "post-Keynesian mainstream economics"; The first is the New Cambridge School.
The General Theory had an important influence on the economic policies of capitalist countries after the First World War. Followers of Keynes tried their best to concretize the policy suggestions put forward in the General Theory, with special emphasis on the role of fiscal policy. In order to adjust the total social demand (including consumption, investment, export, and government purchase of goods and services) and achieve stable economic growth, they put forward measures to stimulate investment and consumption during the depression, such as reducing tax rate, increasing government expenditure, implementing deficit budget, issuing more government bonds, increasing money supply and lowering interest rates. In prosperous times, we should raise tax rates, control government expenditure, control the growth of money supply and raise interest rates to curb investment and consumption. After the advocacy and influence of Keynesians, many post-war capitalist countries have implemented the above-mentioned Keynesian fiscal and financial policies with full employment and economic growth as their policy objectives. Although these policies played a certain role in stimulating economic growth, alleviating the economic crisis and reducing unemployment in the 1950s and 1960s after the war, the fiscal deficit and inflation increased, but the crisis and unemployment were not eliminated because the basic contradictions inherent in capitalism were not and could not be solved. Finally, in the early 1970s, there was a "stagflation" in which high prices and a large number of unemployed people coexisted (see stagflation). In this regard, Keynesians can neither give a self-explanatory explanation nor put forward feasible countermeasures. Even they themselves lament that Keynesian theory is in crisis and needs to be reinterpreted and repaired. The failure of the theory and policy expounded in the General Theory is a reflection of the deepening crisis of the current capitalist system.
The publication of General Theory has aroused great repercussions in the western economic and political fields. Some economists call the publication of General Theory "Keynesian Revolution" in economic theory, and rank it with Smith's The Wealth of Nations and Marx's Das Kapital as three equally great works in the history of economic theory. Since then, Keynesian theory has gradually replaced traditional economics as the orthodox theory of western economics, and the governments of capitalist countries have also adopted Keynesian demand management policies, taking Keynesian theory and suggestions as the guiding ideology for formulating government economic policies. Before the end of 1960s, the economic theories of Keynes and his followers were basically regarded as synonyms of modern macroeconomics by western economists after continuous supplement and improvement. Therefore, some economists call the period from the publication of the General Theory to the mid-1960s the "Keynesian era".
However, since the publication of the General Theory, the debate on the basic ideas and policy propositions of the book has never stopped in the western economic circles. On the one hand, within the Keynesian school, the Keynesian school headed by British Robinson and the Keynesian school headed by American Samuelson have been arguing endlessly. On the other hand, the neo-Austrian school and the monetary school constantly attack Keynesianism from the outside; In particular, neoclassical macroeconomics, including the school of monetary economic cycle (once called the school of rationality and expectation) and the school of real economic cycle, has made a comprehensive attack on Keynesian theory and policy proposition, which has seriously shaken the dominant position of Keynesianism in western macroeconomics. Keynesianism lacks micro-foundation in theory and cannot be consistent with traditional microeconomics. In practice, it is impossible to explain the phenomenon of economic stagnation and inflation at the same time, and there is nothing to do in the face of stagflation, thus falling into a serious crisis. In order to save Keynesianism, the neo-Keynesian economics formed in 1980s provided a micro-foundation for Keynesianism, and restated its theoretical and policy propositions. Due to the emergence of neo-Keynesianism, western macroeconomics has formed a confrontation pattern between neoclassical macroeconomics and neo-Keynesian economics.
The book General Theory not only had a great influence on western economics and the economic policies of capitalist countries in history, but also its theoretical and policy viewpoints still play a role today. Therefore, the study of general theory has not only historical significance, but also practical significance.