Earnings is the sum of three components of personal income-wages and salaries, supplements to wages and salaries, and proprietors' income. It can be used in the analyses of regional economies as a proxy for the income that is generated from participation in current production. Earnings estimates for 1929-47 are assumed to be on a place-of-residence basis; explicit adjustments were made for the principal interstate commuting flows.

"Net earnings" is also presented: This measure is calculated as earnings less contributions for government social insurance plus an adjustment to convert earnings from a place of work to a place of residence basis. The sum of net earnings, personal current transfer receipts, and personal dividend income, personal interest income, and rental income of persons is used in the presentation of state and local area personal income.