Expenditure function

In microeconomics, the expenditure function gives the minimum amount of money an individual needs to spend to achieve some level of utility, given a utility function and the prices of the available goods. In microeconomics, the expenditure function gives the minimum amount of money an individual needs to spend to achieve some level of utility, given a utility function and the prices of the available goods. Formally, if there is a utility function u {displaystyle u} that describes preferences over n commodities, the expenditure function says what amount of money is needed to achieve a utility u ∗ {displaystyle u^{*}} if the n prices are given by the price vector p {displaystyle p} .This function is defined by