Final answer:
The after-tax personal income of consumers is referred to as disposable income, representing the earnings available to spend or save after taxes and government transfers.
Step-by-step explanation:
The after-tax personal income of consumers is known as disposable income. It is the income left after households have paid their taxes and received any government transfers. Disposable income is crucial for making decisions about spending, saving, and budgeting as it represents the amount of money available for households to use. This concept is different from personal income, which refers to total income before taxes, and also distinct from discretionary income, which is the income remaining after paying for necessities and obligations. Disposable income is key in understanding the household budget constraint, which suggests that disposable income can either be spent or saved; thereby affecting consumption patterns and potential savings.