Fundamentals of Business Economics: Scarcity, Markets and the Macro Environment
BA1's business economics domain tests how markets allocate scarce resources and how macro-level forces reshape the environment a business operates in. Expect elasticity calculations, cost and revenue reasoning, and questions linking interest rates, inflation or exchange rates to a business decision.
Scarcity, choice and opportunity cost
- Wants are unlimited and resources finite, so every choice has an opportunity cost - the value of the next best alternative forgone.
- On a production possibility frontier, points on the curve are productively efficient, points inside are inefficient, points beyond are unattainable until resources or technology change.
- Economies of scale (bulk buying, specialisation, spreading fixed costs) lower long-run average cost; diseconomies arise from coordination and motivation problems.
Demand, supply and elasticity
- A price change moves you along the demand curve; changes in income, tastes or substitute prices shift it.
- Equilibrium clears the market. A price ceiling below equilibrium creates a shortage; a wage floor above equilibrium creates surplus labour (unemployment).
- PED = % change in quantity demanded ÷ % change in price. |PED| > 1 is elastic, so a price cut raises total revenue. |PED| < 1 is inelastic, so a price rise raises revenue. More substitutes, longer time horizons and a larger share of income make demand more elastic.
- Income elasticity is positive for normal goods, above 1 for luxuries and negative for inferior goods. Cross elasticity is positive for substitutes and negative for complements.
Market structure and the macro environment
- Perfect competition: price taker, homogeneous product. Monopoly: barriers to entry, price maker. Oligopoly: few rivals, interdependence, non-price competition. Monopolistic competition: many firms, differentiated products.
- Macro variables: real versus nominal GDP, inflation (CPI), unemployment, interest rates, exchange rates. Higher interest rates raise finance costs and tend to strengthen the currency, pressuring exporters.
Worked example
A price rise from $20 to $22 (+10%) cuts demand from 40 to 34 units (−15%). PED = −15 ÷ 10 = −1.5, so demand is elastic. Revenue falls from $800 to $748, so the rise destroys revenue; a small price cut would raise it.
Traps
Confusing a movement along a curve with a shift in it; dropping the minus sign and calling elastic demand 'negative'; assuming elasticity is constant along a straight-line curve; mixing real and nominal GDP; assuming a minimum wage always benefits workers.