Demand shifters vs. supply shifters in market equilibrium

Steps:

• Identify demand curve shifters: factors like income, tastes, or prices of related goods that change quantity demanded at every price.
• Identify supply curve shifters: factors like input costs, technology, or number of sellers that change quantity supplied at every price.
• Evaluate options: Check if each affects buyers' willingness to pay (demand) or sellers' costs/production (supply).
• Select the factor that impacts only demand, not supply.

Why A is correct:

• Income is a non-price determinant of demand; higher incomes increase demand for normal goods like concert tickets, shifting the demand curve rightward (law of demand).

Why the others are wrong:

• B: Rents are input costs for venue owners, shifting the supply curve leftward by raising production costs.
• C: Price changes cause movement along the existing demand curve, not a shift.
• D: Seating capacity affects the quantity of tickets suppliers can produce, shifting the supply curve rightward.

Final answer: A