The Distribution of National Income

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The Washington Center for Equitable Growth has issued a new, very informative report on income inequality. Its authors, Thomas Piketty, Emmanuel Saez, and Gabriel Zucman, are trying to improve on the way economists have measured inequality in the past:

One major problem is the disconnect between maceoeconomics and the study of economic inequality. Macroeconomics relies on national accounts data to study the growth of national income while the study of inequality relies on individual or household income, survey and tax data. Ideally all three sets of data should be consistent, but they are not. The total flow of income reported by households in survey or tax data adds up to barely 60 percent of the national income recorded in the national accounts, with this gap increasing over the past several decades.

Why is there such a discrepancy between the national income accounting and the personal reporting? The main reason is that when people report their income on a survey or a tax return, they are thinking of income actually received in cash. But some forms of national income accrue to individuals whether they see cash from them or not. Employers contribute to workers’ pension plans or subsidize their health insurance. Corporations make money on behalf of shareholders that they retain for investment rather than distribute as dividends. This report aims to apportion the entire national income among individuals. It tries to account for all forms of compensation for workers and all returns on capital assets, whether taken in cash or not.

For purposes of analysis and discussion, the researchers divided the US population into three broad groups, the top tenth, the next two-fifths, and the bottom half. The unit of analysis was the adult individual 20 or older. Most of the analysis split marital income equally between spouses, for example assigning each of them $40,000 if one earned $50,000 and the other $30,000. That makes sense if couples are sharing their purchasing power. The authors also did a separate analysis of gender inequality using individual earnings. There they found that overall, men had 1.75 times as much work income as women, without controlling for hours worked or types of jobs. That ratio has been falling steadily since the 1960s, when it was over 3.00.

Pre-tax income

To appreciate the degree of income inequality the researchers found, consider the familiar analogy of dividing a pie. Imagine that you bake a large pie for a party of ten, dividing it into ten equal slices. But the first guest to dig in takes five slices! The next four guests take one slice each, leaving only one slice to be divided among the remaining five diners. In percentage terms, one-tenth of the people got 50% of the pie, the next two-fifths got 40%, and the remaining half got only 10%.

The real numbers for 2014 (the last year reported) are not far from that. The top tenth got 47.0% of the national income; the next two-fifths got 40.5%, and the bottom half got 12.5%. The average (mean) income for the groups was $304,000 per person for the top 10%, $65,400 for the next 40%, and $16,200 for the bottom 50%. (If some of the numbers sound large, remember that income is being defined very inclusively.)

One advantage of these particular dividing points is that they clearly distinguish between one group whose share of national income is roughly proportional to its size (the two-fifths) and two groups whose share is either disproportionately large (the top tenth) or small (the bottom half).

In addition to the enormous differences in shares, the three groups differed in how much of their income they derived from returns on capital as opposed to their own labor. The top tenth got 43.0% of their income from capital, compared to 17.9% for the next two-fifths and 5.1% for the bottom half. Ironically, in a country that prides itself on its work ethic, the most meager rewards go to those who have to rely the most on their labor.

Trends in inequality

In order to study trends over time, the researchers compared two 34-year periods, 1946-1980 and 1980-2014. The first period includes the postwar economic boom. The second period begins with the year Ronald Reagan was elected president, although I don’t know how much that affected its selection as a dividing point. The authors do suggest that changes in public policy were at least partly responsible for the increase in inequality that has occurred since 1980.

The period after World War II was a time of rapid economic growth and broad-based increases in income. Pre-tax income (adjusted for inflation) increased 79% for the top tenth, 105% for the next two-fifths, and 102% for the bottom half over those 34 years. Because the increase was less for the top tenth than the other groups, the distribution became a little more egalitarian. The share of national income going to the top tenth declined from 37.2% to 34.2%.

The period since 1980 has been a time of both slower economic growth and very unevenly distributed gains. Pre-tax income increased 121% for the top tenth, 42% for the next two-fifths, and only 1% (!) for the bottom half. The rich got richer and the poor got left behind. As a result, the distribution of national income became noticeably less egalitarian. The share of the top tenth rose from 34.2% to 47.0%, but the share of the lower half dropped from 19.9% to 12.5%. That top share is similar to what rich people were getting back in the 1920s, before the Great Depression. Over the course of the past century, income inequality has gone down but then gone back up. At the highest levels of income, the return to inequality has been even more dramatic. Average income for the top 1% increased only 47% during the postwar era, lagging well behind general economic growth; but it rose 205% after 1980, far exceeding general growth. For the top 0.01%, where the average income is over $28 million, the increase has been 454%.

Although global trends such as outsourcing and automation have produced gains for capital at the expense of workers, the authors point out that not all countries have experienced the same extremes of inequality as the United States has. Although economic growth has been slower in France, the lower half of the French population has shared in the national growth as the American lower half has not. As a result, “While the bottom 50 percent of incomes were 11 percent lower in France than in the United States in 1980, they are now 16 percent higher.” America’s self-image as a unique land of opportunity is no longer secure.

Income redistribution?

Pre-tax income does not tell the whole story, however. The taxation of income provides some potential for redistribution, as those with higher incomes are taxed in order to provide some benefits to those with lower incomes. In my next post, I will discuss the report’s comparison of pre- and post-tax income to see how taxes and government benefits are distributed, and what effect they have on income inequality.


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