Using Life Expectancy to Measure Inequality
August 29, 2014
American political discourse is rife with talk of inequality, but Nicholas Eberstadt, resident scholar at the American Enterprise Institute, writes that focusing on economic inequality obscures real gains that have taken place across the globe.
Economic inequality is a misleading figure, because the degree of alleged inequality changes depending upon whether the measure is one of income or consumption, and whether it looks at a person's economic position over a single year or inequality over a lifetime.
There are better ways to assess equality across the world, writes Eberstadt, and he offers two means of measuring it: life expectancy and the distribution of education.
The "Gini coefficient" is what economists use to measure income inequality. The figure ranges from 0 (perfect equality) to 1 (complete inequality, in which one person owns everything). By applying the Gini coefficient to life expectancy, Eberstadt was able to measure the inequality in lifespans. For example:
- In 1751, Swedish life expectancy was as paltry 38 years, with only 70 percent surviving to the age of five. Of those, half lived to the age of 60. In short, as Eberstadt describes it, there was a great deal of inequality in the distribution of survival.
- Using that data, the Gini index for inequality of the age at death in Sweden in 1751 was 0.46. That is roughly equal to the Gini index for incomes in Mexico, which was 0.47 in 2010.
- Today, life expectancy in Sweden is 82 years, and 90 percent of Swedish citizens will reach the age of 65, making the Gini index for inequality at the age of death in Sweden just 0.08.
Eberstadt explains that this trend holds steady across the globe. In the United States, life expectancy was 79 in 2010, up from 61 in 1933. During that time, the Gini index for lifespan inequality was cut in half, falling from 0.22 to 0.11.
As life expectancies have grown, Eberstadt suggests that the globe may have seen a corresponding reduction in health inequality. These are positive improvements and important advances for humans across the globe.
Lastly, more people have access to education:
- Half of all human adults had never received any sort of schooling in 1950, yet, by 2010, only one in every seven adults lacked any education. (In developing countries, this figure was one in six.)
- Average years of schooling have also increased, rising from three in 1950 to eight in 2010. In developed countries, it rose from two in 1950 to seven in 2010.
According to a study by a group of Moroccan economists, the Gini index for the average years of schooling for adults dropped from 0.64 in 1950 to 0.34 in 2010.
Source: Nicholas Eberstadt, "How the World Is Becoming More Equal," Wall Street Journal, August 27, 2014.
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