Budget share

Definition

The budget share of an individual, household, or other economic actor on a good, service, or commodity is defined as the quotient:

${\frac {\mbox{Real expenditure on the commodity}}{\mbox{Real income of the economic actor}}}$

If we assume no saving for or borrowing against the future, then the budget shares for all goods should be nonnegative real numbers that add up to 1.