If consumers always spend 15 percent of their income on clothing, then the income elasticity of demand for clothing is
a. 0.15
b. 1.00
c. 1.15
d. 1.50
e. none of the answer choices

The income elasticity of demand measures how the quantity demanded of a good responds to changes in consumer income. When consumers consistently allocate a fixed percentage of their income to clothing, regardless of how their income changes, the income elasticity of demand equals 1, indicating that clothing expenditure grows proportionally with income.

This means as income rises, spending on clothing also increases at the same rate. Thus, if income increases by 10%, consumers will spend an additional 10% on clothing, confirming that the elasticity is indeed 1.00.