Autonomous consumption refers to the level of consumer spending that is considered essential or necessary regardless of income level. In other words, it represents the minimum amount of spending that individuals or households undertake even when they have zero disposable income.

The concept is a key element in the Keynesian consumption function, which is an economic theory developed by John Maynard Keynes. The consumption function expresses the relationship between disposable income and consumption. It is often represented as:

\[ C = A + MPC \times Yd \]

where:
– \( C \) is total consumption,
– \( A \) is autonomous consumption (the minimum level of consumption when income is zero),
– \( MPC \) is the marginal propensity to consume (the proportion of each additional dollar of income that is spent), and
– \( Yd \) is disposable income.

The term “autonomous” implies that this component of consumption is independent of current income levels. Even if an individual or household has no income, they may still engage in some level of spending for basic necessities, funded through savings or credit.

Factors influencing autonomous consumption include:

1. **Basic Needs:** Expenditures on essential goods and services such as food, shelter, and utilities are often considered part of autonomous consumption.

2. **Fixed Obligations:** Certain fixed obligations, like loan payments or insurance premiums, may contribute to autonomous consumption.

3. **Cultural and Social Factors:** Cultural or social expectations and norms may influence the minimum level of spending individuals consider necessary.

Autonomous consumption is crucial in economic models because it helps determine the baseline level of spending in an economy. Changes in autonomous consumption can influence overall consumption patterns and, consequently, aggregate demand. Policymakers and economists often study these relationships to understand how changes in income, government policies, or other factors might impact consumer spending and, by extension, economic activity.