Macroeconomists

To highlight this decision, macroeconomists downplay the choices among different goods and services. Of course, in reality, households decide both how much to spend and how much to save, and what products to purchase. But it is convenient to treat these decisions separately. The same basic ideas of household decision making apply in either case. Households distribute their income across goods to ensure that no redistribution of that spending would make them better off. This is true whether we are talking about ice cream and frozen yogurt, or about consumption and saving. Households allocate their income between consumption and savings in a way that makes them as well off as possible. They do not spend all their income this year because they want to save some for consumption in the future. Suppose a household in the United States had taxable income of $20,000 in 2010. Some of this income goes to the payment of taxes to federal and state governments. (From our earlier discussion, the average federal tax rate is 13.25 percent.) The rest is either spent on goods and services or saved. The income that is spent on goods and services today is spread over the many products that a household buys. The income that is saved will likewise be used in the future to purchase different goods and services. Personal Income and Disposable Income The most basic measure of aggregate economic activity is real GDP, which is the total amount of final goods and services produced in our economy over a period of time, such as a year. The rules of national income accounting mean that real GDP measures three different things at once: the production or output of the economy, the spending in the economy; and the income generated in the economy. We use real GDP as our most general measure of income. We work in this chapter with two further concepts of income from the national accounts:personal income and disposable income. Some of the income generated in the economy is retained by firms to finance new investment, so it does not go to households. Personal income refers to that portion of GDP that finds its way directly into the hands of households. (At the level of an individual household, it corresponds closely to adjusted gross income on the tax form.) Disposable income is what remains after we subtract from personal income the taxes paid by households to the government and add to personal income the transfers (such as welfare payments) received by households from the government. For a household, disposable income measures its available resources after taxes have been paid and transfers received. Consumption Smoothing Our starting point for understanding consumption choices is the household budget constraint for a typical household. The household receives income from working and other sources and pays taxes to the government. The remainder is the household’s disposable income. The household budget constraint reminds us that, ultimately, you must either spend the income you receive or save it; there are no other choices. That is, disposable income = consumption + saving. A theory of consumption is a theory of how households decide to divide their income between consumption and saving. Saving is a way to convert current income into future consumption. A theory of consumption is equivalently a theory of saving.