propensity to consume
in economics, the proportion of total income or of an increase in income that consumers tend to spend on goods and services rather than to save. The ratio of total consumption to total income is known as the average propensity to consume; an increase in consumption caused by an addition to income divided by that increase in income is known as the marginal propensity to consume. Because households divide their incomes between consumption expenditures and saving, the sum of the propensity to consume and the propensity to save will always equal one.
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