Disposable income is what is left to the family after taxes.
Family expenditures are figured from disposable income. The US savings rate is among the lowest in the industrialized world. Discretionary income is what is left of disposable income after paying for necessities. Like disposable income, this too can be hard for marketers to identify because families differ on what they consider necessities. Even basic necessities such as food, clothing, and shelter, take on different product forms that in turn may vary in cost.