Induced consumption is the portion of consumption that varies with disposable income. When a change in disposable income “induces” a change in consumption on goods and services, then that changed consumption is called “induced consumption”. In contrast, expenditures for autonomous consumption do not vary with income. For instance, expenditure on a consumable that is considered a normal good would be considered to be induced.
In the simple linear consumption function,
Consumer spending is the total money spent on final goods and services by individuals and households.
There are two components of consumer spending: induced consumption (which is affected by the level of income) and autonomous consumption (which is not).
Autonomous consumption (also exogenous consumption, autonomous spending) is the consumption expenditure that occurs when income levels are zero. Such consumption is considered autonomous of income only when expenditure on these consumables does not vary with changes in income; generally, it may be required to fund necessities and debt obligations. If income levels are actually zero, this consumption counts as dissaving, because it is financed by borrowing or using up savings. Autonomous consumption contrasts with induced consumption, in that it does not systematically fluctuate with income, whereas induced consumption does. The two are related, for all households, through the consumption function: