⚠️ Opening the cheat sheet costs $25,000 in company performance — use wisely!
📉 Price Elasticity of Demand
PED = %ΔQd ÷ %ΔP
|PED| > 1: elastic · |PED| < 1: inelastic · |PED| = 1: unit elastic
🔗 Cross-Price Elasticity
XED = %ΔQd(A) ÷ %ΔP(B)
Positive = substitutes · Negative = complements · Keep the sign!
💰 Income Elasticity
YED = %ΔQd ÷ %ΔIncome
YED > 1 = luxury · 0–1 = normal · negative = inferior
📦 Price Elasticity of Supply
PES = %ΔQs ÷ %ΔP
PES > 1 = elastic supply · PES < 1 = inelastic supply