Measuring Total Output and Income

Read this chapter, to learn about measuring domestic output, and attempt the "Try It" exercises. The material in this chapter concentrates on the four components of GDP: consumption, investment, government purchases, and net exports. Pay attention to the definition of these components as it may differ from your expectations. For example, note that Investment does not refer to the common knowledge definition of investment as in the trading of stock and bonds. Instead, the Investment component refers mainly to the purchase of physical machinery and equipment needed in the production of goods and services. You will revisit certain sections of the chapter later in this unit.

6.2 Measuring Total Income

Tracing Income from the Economy to Households

We have seen that the production of goods and services generates income for households. Thus, the value of total output equals the value of total income in an economy. But we have also seen that our measure of total income, GDI, includes such things as depreciation and indirect business taxes that are not actually received by households. Households also receive some income, such as transfer payments, that does not count as part of GDP or GDI. Because the income households actually receive plays an important role in determining their consumption, it is useful to examine the relationship between a nation's total output and the income households actually receive.

Table 6.3 "From GDP to Disposable Personal Income" traces the path we take in going from GDP to disposable personal income, which equals the income households have available to spend on goods and services. We first convert GDP to GNP and then subtract elements of GNP that do not represent income received by households and add payments such as transfer payments that households receive but do not earn in the production of GNP. Disposable personal income is either spent for personal consumption or saved by households.

Table 6.3 From GDP to Disposable Personal Income

GDP + net factor earnings from abroad = gross national product (GNP)
GNP − depreciation (consumption of fixed capital) = net national product (NNP)
NNP − statistical discrepancy = national income (NI)
NI − income earned but not received [e.g., taxes on production and imports, social security payroll taxes, corporate profit taxes, and retained earnings] + transfer payments and other income received but not earned in the production of GNP = personal income (PI)
PI − personal income taxes = disposable personal income (DPI)

GDP, a measure of total output, equals GDI, the total income generated in the production of goods and services in an economy. The chart traces the path from GDP to disposable personal income, which equals the income households actually receive. We first convert GDP to GNP. Then, we subtract depreciation to obtain net national product and subtract the statistical discrepancy to arrive at national income (i.e., gross national income [GNI] net of depreciation and the statistical discrepancy). Next, we subtract components of GNP and GNI that do not represent income actually received by households, such as taxes on production and imports, corporate profit and payroll taxes (contributions to social insurance), and corporate retained earnings. We add items such as transfer payments that are income to households but are not part of GNP and GNI. The adjustments shown are the most important adjustments in going from GNP and GNI to disposable personal income; several smaller adjustments (e.g., subsidies, business current transfer payments [net], and current surplus of government enterprises) have been omitted.