Which of the following would shift the supply curve for guitars?

• A. A decrease in the price of wood used to make guitars
• B. An increase in the price of guitars
• C. A change in consumer preferences for electric guitars
• D. A rise in consumer income

Answer: (A)

Verified step by step guidance

1. Understand that the supply curve represents the relationship between the price of a good and the quantity that producers are willing to supply, holding other factors constant.
2. Identify factors that cause the supply curve to shift. These include changes in input prices, technology, number of sellers, expectations, and government policies—not changes in the good's own price.
3. Analyze each option: An increase in the price of guitars affects quantity supplied along the supply curve, not the curve itself; a change in consumer preferences and a rise in consumer income affect demand, not supply.
4. Focus on the option 'A decrease in the price of wood used to make guitars' because wood is an input in guitar production. A decrease in input cost reduces production costs, allowing producers to supply more at each price, shifting the supply curve to the right.
5. Conclude that only changes in input prices, like the price of wood, shift the supply curve, while changes in the good's own price or demand factors shift quantity supplied or demand curves, respectively.