AP Microeconomics Variables

Symbol/Variable

Meaning

Q

Quantity

P

Price

TR

Total Revenue

AR

Average Revenue (same as Price in perfect competition)

MR

Marginal Revenue

TC

Total Cost

FC

Fixed Cost

VC

Variable Cost

ATC

Average Total Cost

AFC

Average Fixed Cost

AVC

Average Variable Cost

MC

Marginal Cost


🎯 Production Variables:

Symbol/Variable

Meaning

TP

Total Product (output)

MP

Marginal Product

AP

Average Product


🎯 Labor & Resource Markets:

Symbol/Variable

Meaning

MRP

Marginal Revenue Product

MRC

Marginal Resource Cost (same as wage in perfect competition)


🎯 Elasticity Variables:

Symbol/Variable

Meaning

Ed

Price Elasticity of Demand

Es

Price Elasticity of Supply

Exy

Cross-Price Elasticity

Ei

Income Elasticity


🎯 Externalities & Market Failure:

Symbol/Variable

Meaning

MSC

Marginal Social Cost

MPC

Marginal Private Cost

MSB

Marginal Social Benefit

MPB

Marginal Private Benefit


Extra tips:

  • Δ (delta) = “change in” → used in marginal formulas (e.g., MC = ΔTC / ΔQ).

  • MR = MC → rule for maximizing profit.