Micro Ch8 CheatSheet

Application: The Costs of Taxation

Overview of Tax Effects

• A tax introduces a wedge between the price buyers pay and the price sellers receive

Total Surplus and Deadweight Loss

• Total Surplus (TS), the sum of CS and PS, is maximized in market equilibrium without a tax.

• A per-unit tax ($T$) decreases both CS and PS. Tax revenue = $T \times Q_T$.

• The Deadweight Loss (DWL) represents the reduction in total surplus that is not re-captured as tax revenue. It signifies the units of goods or services that are no longer traded due to the tax, leading to a loss of economic welfare.

Determinants of Deadweight Loss

• The size of DWL is directly influenced by price elasticities of supply and demand.

• Higher elasticities (meaning quantity supplied or demanded is highly responsive to price changes) result in larger DWL because a tax induces a more significant reduction in quantity traded.

• Lower elasticities lead to smaller DWL, as the tax has less impact on transaction volumes.

The Laffer Curve and Tax Revenue

• As tax rates increase, the deadweight loss grows at a more rapid rate than the increase in tax size itself.

• The Laffer Curve illustrates that while tax revenue initially increases with higher tax rates, it can eventually reach a peak and then begin to decrease if tax rates become excessively high, as the elevated taxes drastically shrink the overall market for goods and services.

Conclusion

• Taxation aims to strike a balance between generating government revenue and minimizing economic distortion.

• Taxes inherently lead to a loss of economic welfare (DWL), and the combined decrease in consumer and producer surplus frequently surpasses the revenue collected by the government.

• The relationship between market elasticities and the size of the tax significantly determines both the extent of DWL and its impact on total tax revenue.