concept of new classical school and new keynesian
New Keynesian economics Two main assumptions define the New Keynesian approach to macroeconomics. Like the New Classical approach, New Keynesian macroeconomic analysis usually assumes that households and firms have rational expectations. But the two schools differ in that New Keynesian analysis usually assumes a variety of market failures. In particular, New Keynesians assume that there is imperfect competition[1] in price and wage setting to help explain why prices and wages can become "sticky", which means they do not adjust instantaneously to changes in economic conditions.
World-systems theory Immanuel Wallerstein has developed the best-known version of world-systems analysis, beginning in the 1970s.[5][6] Wallerstein traces the rise of the capitalist world-economy from the "long" 16th century (c. 1450–1640). The rise of capitalism, in his view, was an accidental outcome of the protracted crisis of feudalism (c. 1290–1450).[7] Europe (the West) used its advantages and gained control over most of the world economy and presided over the development and spread of industrialization and capitalist economy, indirectly resulting in unequal development.[2][3][6]