Supply, Demand, Price Controls, and Tax Incidence: Key Concepts and Applications

Price Controls in Markets

Shortages and Surpluses from Price Ceilings

Price ceilings are government-imposed limits on how high a price can be charged for a product. They are typically set below the equilibrium price, leading to market distortions.

• Shortage: Occurs when the quantity demanded exceeds the quantity supplied at the ceiling price.

• Surplus: Occurs when the quantity supplied exceeds the quantity demanded, typically associated with price floors.

• Short-Run vs. Long-Run Effects: The shortage created by a price ceiling is greater in the short run than in the long run, as market participants adjust over time.

• Surplus from Price Ceiling: The surplus created by a price ceiling is greater in the long run than in the short run.

• Example: If the government sets a price ceiling on gasoline at $4.00 per gallon and the equilibrium price is $3.00, the ceiling is not binding. However, if demand increases, the ceiling may become binding, causing shortages.

Market Lobbying for Price Floors

Price floors are minimum prices set by the government, usually above equilibrium, to benefit sellers.

• Sellers: More likely to lobby for price floors, as these guarantee higher prices for their goods.

• Buyers: Generally oppose price floors, as they lead to higher prices and potential surpluses.

Supply and Demand Model: Tax Incidence

Effects of Taxes on Market Equilibrium

Taxes can be levied on either buyers or sellers, affecting market outcomes and shifting supply or demand curves.

• Tax on Sellers: Shifts the supply curve upward by the size of the tax per unit.

• Tax on Buyers: Shifts the demand curve downward by the size of the tax per unit.

• Tax Burden: The economic burden of a tax is shared between buyers and sellers, regardless of whom the tax is levied upon.

• Formula: The division of tax burden depends on the relative elasticities of supply and demand.

• Example: If a tax is collected from buyers, the burden is the same as if it were collected from sellers.

Distribution of Tax Burden

The incidence of a tax refers to how the burden of the tax is distributed between buyers and sellers.

• Elasticity: If demand is less elastic than supply, buyers bear more of the tax burden.

• Necessities: Taxes on necessities tend to fall more heavily on buyers, as their demand is less elastic.

• Example: A tax on gasoline, a necessity, will likely be borne more by buyers than sellers.

Consumer Surplus

Definition and Calculation

Consumer surplus is a measure of the economic benefit to buyers, representing the difference between what consumers are willing to pay and what they actually pay.

• Definition: The difference between a buyer's willingness to pay and the actual price paid.

• Formula: $\text{Consumer Surplus} = \text{Willingness to Pay} - \text{Market Price}$

• Example: If Paolo is willing to pay $140 for a 3D printer and the market price is $60, his consumer surplus is $80.

• Market Consumer Surplus: The total consumer surplus in a market is the sum of individual surpluses for all buyers who purchase the good at the market price.

Application Example

• Given a market price of $60 for a 3D printer, only buyers willing to pay at least $60 will purchase.

• If three buyers (Paolo, Sharon, and Van) are willing to pay more than $60, total consumer surplus is the sum of their individual surpluses.

Summary Table: Effects of Price Controls and Taxes

Policy	Effect on Market	Who Benefits?	Who Bears Burden?
Price Ceiling	Creates shortage if below equilibrium price	Buyers (lower prices)	Sellers (lower revenue)
Price Floor	Creates surplus if above equilibrium price	Sellers (higher prices)	Buyers (higher cost)
Tax on Sellers	Supply curve shifts up; price rises, quantity falls	Government (tax revenue)	Shared by buyers and sellers
Tax on Buyers	Demand curve shifts down; price falls, quantity falls	Government (tax revenue)	Shared by buyers and sellers

Additional info: These concepts are foundational in microeconomics and are relevant for understanding market interventions, but are not directly part of Financial Accounting. However, they may be covered in introductory accounting or business courses for context.