Answer:
the income effect.
Step-by-step explanation:
The income effect describes a change in demand of goods which is caused by a change in the income. Income effect changes the quantity of good and services purchased by the customers.
There is a reduction in the quantity of goods demanded by customers when their income reduces and an increase in the quantity demanded when they experience an increase in their income.
Rodi the owner of Hallman's auto repair service has observed that customers keep their high-mileage cars longer when the economy is not doing well, thereby creating demand for his maintenance and repair, this is as a result of a decrease in their amount of income.