Government Actions in Markets: Taxes, Incidence, and Deadweight Loss

Government Actions in Markets

Introduction

This chapter explores how government interventions, particularly taxes, affect market outcomes, efficiency, and the distribution of economic burdens between buyers and sellers. Key concepts include tax incidence, deadweight loss (DWL), and the practical and fairness perspectives of taxation.

Impact of Tax

Tax Incidence

Tax incidence refers to the division of the tax burden between buyers and sellers in a market. It is determined by the relative elasticities of demand and supply, not by who is legally responsible for paying the tax.

• Definition: Tax incidence is the analysis of who ultimately bears the economic burden of a tax.

• Key Point: The party (buyer or seller) with the more inelastic curve bears a greater share of the tax burden.

• Example: If demand is inelastic and supply is elastic, buyers bear most of the tax burden.

Paying vs. Bearing the Tax

Paying a tax does not necessarily mean bearing its economic burden. The true burden depends on market elasticities.

• Who pays vs. who bears: The statutory incidence (who pays the tax to the government) can differ from the economic incidence (who bears the cost).

• Elasticity effect: The more elastic the demand or supply, the less that side bears the tax burden.

• Independence from statutory assignment: The division of the tax burden is independent of whether the tax is levied on buyers or sellers.

Worked Example: Tax Incidence in the Sugar Market

Suppose the sugar market in Hong Kong is perfectly competitive:

• Market demand: $Q_D = 500 - 30P$

• Market supply: $Q_S = 20P$

Equilibrium Price:

• Set $Q_D = Q_S$:

• $500 - 30P = 20P$

• $500 = 50P$

• $P^* = 10$

Case 1: $1 Tax on Buyers

• Buyers pay $P_B = P + 1$

• Sellers receive $P_S = P$

• Set $Q_D = Q_S$:

• $Q_D = 500 - 30(P + 1)$

• $Q_S = 20P$

• Equilibrium: $500 - 30(P + 1) = 20P$

• $500 - 30P - 30 = 20P$

• $470 = 50P$

• $P = 9.4$

• $P_B = 9.4 + 1 = 10.4$

• Tax burden: Buyers = $10.4 - 10 = 0.4$; Sellers = $10 - 9.4 = 0.6$

Case 2: $1 Tax on Sellers

• Buyers pay $P_B = P$

• Sellers receive $P_S = P - 1$

• $Q_D = 500 - 30P$

• $Q_S = 20(P - 1)$

• Equilibrium: $500 - 30P = 20(P - 1)$

• $500 - 30P = 20P - 20$

• $520 = 50P$

• $P = 10.4$

• $P_S = 10.4 - 1 = 9.4$

• Tax burden: Sellers = $10 - 9.4 = 0.6$; Buyers = $10.4 - 10 = 0.4$

Conclusion: The economic burden is the same regardless of whether the tax is levied on buyers or sellers.

Elasticity and Tax Burden

Elasticity of Demand and Supply

The elasticity of demand and supply determines how the tax burden is shared:

• Inelastic demand: Buyers bear more of the tax.

• Elastic demand: Sellers bear more of the tax.

• Inelastic supply: Sellers bear more of the tax.

• Elastic supply: Buyers bear more of the tax.

Summary Table:

Elasticity	Who Bears More Tax?
Inelastic Demand	Buyers
Elastic Demand	Sellers
Inelastic Supply	Sellers
Elastic Supply	Buyers

Applications

• Luxury Tax: Imposed on goods with elastic demand and inelastic supply (e.g., yachts). Suppliers bear most of the tax burden.

• Food Tax: If food demand is inelastic, buyers (often poorer consumers) bear most of the tax burden, regardless of whether the tax is levied on sellers.

Taxes and Deadweight Loss (DWL)

Deadweight Loss and Efficiency

Taxes create inefficiency in markets by reducing the quantity traded below the equilibrium level, resulting in deadweight loss (DWL).

• Definition: Deadweight loss is the reduction in total surplus that results from a market distortion, such as a tax.

• Formula: DWL is typically represented as the area of the triangle between the supply and demand curves, from the equilibrium quantity to the quantity after tax.

• Example: A $200 tax on tablets reduces consumer and producer surplus, creating DWL.

Determinants of DWL

• Elasticity of supply and demand: The more elastic either curve, the greater the DWL from a tax.

• Inelastic supply or demand: DWL is smaller because quantity traded falls less.

• Elastic supply or demand: DWL is larger because quantity traded falls more.

Summary Table:

Elasticity	DWL Size
Inelastic Demand/Supply	Small DWL
Elastic Demand/Supply	Large DWL

Taxes in Practice

Efficiency Perspective

Governments often tax goods with inelastic demand or supply to minimize DWL and maximize revenue.

• Examples: Alcohol, tobacco, gasoline (inelastic demand).

• Labor: Labor supply is relatively inelastic, so workers bear most of the burden of income and payroll taxes.

Fairness Perspective

Taxation can also be evaluated based on fairness, using principles such as the benefits principle and the ability-to-pay principle.

• Benefits Principle: Those who benefit from public services should pay for them (e.g., fuel taxes for highways).

• Ability-to-Pay Principle: Those with greater ability to pay (higher incomes) should bear more of the tax burden.

Summary of Intended Learning Outcomes

• Explain the effects of tax on market outcomes.

• Identify who actually bears the tax burden.

• Analyze tax's impact on efficiency and deadweight loss.

• Understand the principles of levying taxes in practice: efficiency and fairness perspectives.

• Describe the impact of price ceilings and price floors, including minimum wage in labor markets.

Additional info: Some equations and tables were expanded for clarity and completeness. The notes also infer standard microeconomic theory where original slides were fragmented or brief.