Which of the following would cause a leftward shift in the supply curve for car washes?

• A. A decrease in the price of water used in car washes
• B. An increase in the wages paid to car wash employees
• C. A decrease in the price of car washes
• D. An improvement in car wash technology

Answer: (B)

Verified step by step guidance

1. Understand that a leftward shift in the supply curve means a decrease in supply at every price level, which typically happens when production becomes more costly or less efficient.
2. Analyze each option to see how it affects the cost or ability to supply car washes:
3. A decrease in the price of water (an input) lowers production costs, which would increase supply, causing a rightward shift, not leftward.
4. An increase in wages paid to car wash employees raises production costs, making it more expensive to supply car washes, which would cause the supply curve to shift leftward.
5. A decrease in the price of car washes affects the quantity supplied (movement along the curve), not the supply itself, so it does not shift the supply curve.
6. An improvement in car wash technology makes production more efficient, lowering costs and increasing supply, causing a rightward shift.