Demand shifters vs. supply shifters in ticket markets

Steps:

• Recall that demand curve shifts from non-price factors like buyer incomes, while supply shifts from seller costs or capacity.
• Identify option A as a buyer-side factor affecting willingness to pay for concerts.
• Check options B, C, D for seller-side or price effects that impact supply or cause movements.
• Confirm A uniquely shifts demand without altering supply.

Why A is correct:

• Income changes alter consumers' purchasing power, shifting the demand curve rightward (higher income) or leftward (lower income) per the income effect in demand theory.

Why the others are wrong:

• B: Higher rents raise venue costs, shifting the supply curve leftward.
• C: Ticket price changes cause movement along the existing demand curve, not a shift.
• D: Increased seating expands ticket supply, shifting the supply curve rightward.

Final answer: A