The length of a business cycle is the period business cycle time containing a single boom and contraction in sequence. Business cycles are usually measured by considering the growth rate of real gross domestic product. Despite the often-applied term cycles, these fluctuations in economic activity do not exhibit uniform or predictable periodicity.
The common or popular usage boom-and-bust cycle refers to fluctuations in which the expansion is rapid and the contraction severe. The first systematic exposition of economic crises, in opposition to the existing theory of economic equilibrium, was the 1819 Nouveaux Principes d’économie politique by Jean Charles Léonard de Sismondi. Sismondi’s theory of periodic crises was developed into a theory of alternating cycles by Charles Dunoyer, and similar theories, showing signs of influence by Sismondi, were developed by Johann Karl Rodbertus. Business cycle with it specific forces in four stages according to Malcolm C. In 1860 French economist Clement Juglar first identified economic cycles 7 to 11 years long, although he cautiously did not claim any rigid regularity.
Schumpeter’s Juglar model associates recovery and prosperity with increases in productivity, consumer confidence, aggregate demand, and prices. Interest in the different typologies of cycles has waned since the development of modern macroeconomics, which gives little support to the idea of regular periodic cycles. A simplified Kondratiev wave, with the theory that productivity enhancing innovations drive waves of economic growth. There were great increases in productivity, industrial production and real per capita product throughout the period from 1870 to 1890 that included the Long Depression and two other recessions. Over the period since the Industrial Revolution, technological progress has had a much larger effect on the economy than any fluctuations in credit or debt, the primary exception being the Great Depression, which caused a multi-year steep economic decline. 22 in 1990, measured in 2010 dollars.