Final answer:
When gasoline prices decrease simultaneously with an income increase, the demand for vehicle ownership would likely increase. On the supply side, the decrease in gasoline prices might also affect the supply of vehicles.
Step-by-step explanation:
When gasoline prices decrease simultaneously with an income increase, the demand for vehicle ownership would likely increase. This is because lower gasoline prices make owning a vehicle more affordable, while an increase in income provides individuals with the financial means to purchase and maintain a vehicle. As a result, the demand curve for vehicles would shift to the right, indicating a higher quantity demanded at each price level.
On the supply side, the decrease in gasoline prices might also affect the supply of vehicles. Lower gasoline prices would make fuel-efficient vehicles less desirable, potentially leading manufacturers to reduce production of these vehicles. This could result in a leftward shift of the supply curve for fuel-efficient vehicles.