Macroeconomics

The term "business cycle" was popularized by Wesley Mitchell, one of the founders of the National Bureau of Economic Research (NBER)

Joseph Schumpeter viewed business cycles as the “heartbeat” of capitalism

Keynesian theory introduced the idea that business cycles are demand-driven, not just supply-side phenomena.

Real Business Cycle (RBC) Theory claims that economic fluctuations are efficient responses to real shocks—such as technology or productivity changes—rather than market failures.

Clément Juglar, a French economist, was one of the first to identify regular business cycles (~7–11 years) back in the 1860s—long before the term was popular.

Marxian theory saw business cycles as inherent contradictions of capitalism.