Business Cycles — Phases, Causes, and Indicators
Foundation of macroeconomics for Paper 4. Master the four phases, leading vs lagging indicators, and the standard policy responses.
Last reviewed: 25 April 2026
The four phases
- •Expansion: rising output, employment, incomes, and inflation. Confidence high.
- •Peak: turning point — output and employment plateau at maximum.
- •Contraction (Recession): output and employment fall. Income and consumption decline. Two consecutive quarters of negative GDP growth = technical recession.
- •Trough: low point. The economy bottoms out before recovery.
- •After trough → Recovery → Expansion. The cycle repeats.
Causes (theories)
- •Monetary theory: changes in money supply → demand swings.
- •Innovation theory (Schumpeter): bursts of innovation drive expansion; absorption causes downturn.
- •Multiplier-accelerator (Samuelson-Hicks): investment changes amplified through induced consumption.
- •External shocks: oil prices, wars, pandemics, supply chain disruptions.
- •Psychological: business confidence, herd behaviour.
Indicators
- •Leading: stock prices, building permits, new orders for capital goods, money supply (M3), consumer expectations.
- •Coincident: GDP, industrial production, employment, retail sales.
- •Lagging: unemployment rate, CPI, inventory-to-sales ratio, business spending on capital.
Policy responses
- •Recession → expansionary monetary (lower repo rate, OMO purchases) + expansionary fiscal (higher govt spending, tax cuts).
- •Boom / inflation → contractionary monetary (higher repo, OMO sales) + contractionary fiscal (cut spending, raise taxes).
- •RBI's tools: Repo, Reverse Repo, CRR, SLR, OMO, MSF.
- •Government tools: budget deficit/surplus, public investment, tax structure.
Must know before the exam
- ★Inflation typically rises in expansion and falls in contraction (with lag).
- ★Unemployment is a LAGGING indicator — falls late in expansion, rises late in contraction.
- ★The 2008 GFC and the 2020 pandemic recession are textbook examples in current ICAI material.
- ★Stagflation = high inflation + high unemployment (the rare nasty case).
Common mistakes & fixes
- ✗ Calling 'recovery' a separate phase from 'expansion'.
- ✓ Recovery is the early stage of expansion. Most ICAI questions list 4 phases: expansion / peak / contraction / trough.
- ✗ Treating CRR and SLR as the same.
- ✓ CRR is held with RBI as cash. SLR is held by the bank itself in approved securities (govt bonds, gold, cash).
Lock it in with practice
Reading without practising is the #1 reason people forget in the exam. Solve a quick set while this is fresh.