2.7

Role of Government in Microeconomics

Price controls, indirect taxes, subsidies, and their effects on markets and stakeholders.

You should be able to
  • Explain why governments intervene in markets
  • Analyse the effects of price ceilings and price floors on consumers, producers, and efficiency
  • Explain indirect taxes and analyse their effects on price, quantity, CS, PS, government revenue, and DWL
  • Explain the incidence of a tax and how PED affects it
  • Calculate the effects of price controls and taxes on markets HL

Why Governments Intervene

Government intervention in markets can aim to:

  • Earn government revenue
  • Support firms or households on low incomes
  • Influence the level of production or consumption
  • Correct market failure
  • Promote equity

Price Controls

Price controls regulate prices above or below the market equilibrium.

Price ceiling (maximum price)

Set below the equilibrium to make goods more affordable. To be effective, it must be below the equilibrium price.

StakeholderEffect
Consumers who can buyBetter off — pay a lower price
Consumers who cannot buyWorse off — shortage means some cannot get the good
ProducersWorse off — receive lower price, sell less; revenue falls
SocietyDeadweight loss (DWL) — allocative inefficiency

A black market can arise: firms or consumers illegally charge a price above the legal maximum to clear the shortage.

A price ceiling set below equilibrium, creating a shortage where quantity demanded exceeds quantity supplied
A binding ceiling below Pe: quantity supplied (Qs) falls short of quantity demanded (Qd), creating a shortage.
Welfare effects of a price ceiling showing consumer surplus, producer surplus and deadweight loss
Welfare effects: output falls to Q₁, producer surplus shrinks, and a deadweight loss (red) appears.

Price floor (minimum price)

Set above the equilibrium to increase the price producers receive. To be effective, it must be above the equilibrium price.

StakeholderEffect
Producers who sellBetter off — receive a higher price
ConsumersWorse off — pay a higher price and buy less
Unsold producersWorse off — surplus means some producers cannot sell
SocietyDeadweight loss — allocative inefficiency; surplus may require government purchase
A price floor set above equilibrium, creating a surplus where quantity supplied exceeds quantity demanded
A binding floor above Pe: quantity supplied (Qs) exceeds quantity demanded (Qd), creating a surplus.
Welfare effects of a price floor showing consumer surplus, producer surplus and deadweight loss
Welfare effects: output falls to Q₁, consumer surplus shrinks, and a deadweight loss (red) appears.

Indirect Taxes

An indirect tax is a tax imposed on expenditure on goods and services. "Indirect" because consumers pay the producer, and the producer pays the government — the producer is the key actor in collection and payment.

Types

  • Specific tax: fixed amount per unit (e.g. $2 per packet of cigarettes)
  • Ad valorem tax: a percentage of the selling price (e.g. 20% VAT)

Why governments use indirect taxes

  • Raise government revenue
  • Reduce consumption of demerit goods or goods with negative externalities
  • Broaden the tax base

Effect on the market

The tax is paid by producers → it increases costs → supply shifts left (decreases). The vertical distance between the original and new supply curves equals the tax per unit. New equilibrium: higher price for consumers, lower price received by producers, lower quantity.

A specific tax shifting supply up to S plus tax, with consumer price Pc, producer price Pp, tax revenue and deadweight loss
The tax shifts supply to S + tax. Consumers pay Pc, producers keep Pp; the box is government revenue and the red triangle is the deadweight loss.

Effects on stakeholders

StakeholderEffect
ConsumersPay a higher price (Pc); buy less
ProducersReceive a lower price (Pp = Pc − tax per unit); sell less; revenue falls
GovernmentGains tax revenue = tax per unit × quantity sold (Qt)
WorkersMay see increased unemployment as quantity produced falls
SocietyDeadweight loss — small triangle of lost social surplus

Tax incidence

Tax incidence refers to who actually bears the burden of the tax. This depends on PED:

  • Inelastic demand: consumers bear more of the tax — they cannot easily reduce quantity demanded, so producers can pass most of the tax on as higher prices
  • Elastic demand: producers bear more of the tax — if they raise prices, Qd falls sharply, so producers absorb more of the cost
Two panels showing the tax burden falling mostly on consumers when demand is inelastic and mostly on producers when demand is elastic
The same tax: with inelastic demand consumers bear most of the burden; with elastic demand producers bear most.

Subsidies

A subsidy is a payment from the government to producers, lowering their costs and shifting supply right (down) to S + subsidy. Producers receive a higher price (Pp), consumers pay a lower price (Pc), and quantity rises.

A subsidy shifting supply down to S plus subsidy, with producer price Pp, consumer price Pc, total subsidy cost and deadweight loss
The subsidy shifts supply to S + subsidy. Producers receive Pp, consumers pay Pc; the box is the total cost to government and the red triangle is the deadweight loss from overprovision.
Materials to come

Fuller notes on subsidies — their effects on consumers, producers, government spending, and efficiency — will be added here.

Materials to come

Practice questions for this topic will be added here.