Advanced Macro & GrowthadvancedConcept explainer

Real Business Cycle Theory

Business cycles as efficient responses to technology shocks, the provocation that built modern macro.

Definition

RealrealAdjusted for inflation, measured in actual purchasing power. Business Cycle theory: fluctuations as optimal responses of rational agents to technology shocks, in a frictionless flexible-price economy, cycles without market failure.

Key equation

Core mechanism: TFP shock → MPL↑ → work more today (intertemporal substitution) → output amplifies

The intuition

If productivity is temporarily high, it's rational to work and invest extra now and rest later, so even efficient economies fluctuate. The provocation: if cycles are optimal, stabilization policy is pointless. New Keynesians answered by adding sticky pricessticky pricesPrices and wages that adjust slowly, giving demand shocks real short-run effects. back.

Exam tip

Know the two standard critiques: measured 'technology regress' in recessions is implausible, and labor supply isn't that elastic.

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Real Business Cycle Theory · economics explainer · Graphl