Which of the following would cause a rightward shift of the supply curve for cell-phone services?

• A. A decrease in the number of cell-phone service providers
• B. An increase in the price of cell-phone services
• C. A decrease in the cost of providing cell-phone services
• D. A rise in consumer income

Answer: (C)

Verified step by step guidance

1. Understand that a rightward shift of the supply curve means an increase in supply, which occurs when producers are willing and able to supply more of the good at every price.
2. Recall that changes in the price of the good itself cause movements along the supply curve, not shifts of the supply curve. So, an increase in the price of cell-phone services will not shift the supply curve but will cause a movement along it.
3. Recognize that a decrease in the number of cell-phone service providers reduces the total market supply, causing a leftward shift, not a rightward shift.
4. Identify that a decrease in the cost of providing cell-phone services lowers production costs, making it more profitable to supply more at every price, which causes the supply curve to shift rightward.
5. Note that a rise in consumer income affects demand, not supply, so it does not cause a shift in the supply curve.