Alan Krueger, Chair of President Obama’s Council of Economic Advisers, gave a talk a few weeks ago on inequality. Krueger described the sharp increase in income inequality in the United States since the 1970s and discussed some undesirable consequences it may have. One of those consequences is reduced intergenerational mobility (relative intergenerational income mobility, to be more precise). Krueger provided a graph showing that nations with greater income inequality tend to have a stronger correlation between the earnings of parents and their children (less mobility). This has sparked a wide-ranging discussion about the link between income inequality and mobility (Winship, Corak, Winship, Corak, Cowen, Yglesias, Wolfers, Smith, Winship, Quiggin, Cowen, Quiggin, Bernstein).
Here’s what the pattern looks like according to Miles Corak, the source of Krueger’s data (enlarged version here). The vertical axis in the chart is immobility; lower means more mobility. The horizontal axis is income inequality a few decades earlier.
Nations with lower income inequality tend to have more intergenerational mobility, and the association is quite strong. There are concerns about the data. But suppose the data are accurate, and suitable for testing this link. What does the association depicted in this chart tell us about the magnitude of inequality’s impact? How much would reducing income inequality in the United States help?
For most, the aim isn’t high intergenerational mobility per se; it’s low inequality of opportunity. Mobility serves as an indicator (not perfect, but not bad) of equality of opportunity.
Money ought to be good for children’s opportunity. Kids growing up in households with higher incomes are more likely to have good health care, low stress, learning-centered preschools, good elementary and secondary schools, extracurricular activities that promote cognitive skills and earnings-enhancing noncognitive traits, and access to a strong university. It would be surprising, therefore, if inequality of parents’ incomes did not contribute to inequality of opportunity among their children.
But how large is the effect? After all, money isn’t the only thing that matters; a good bit of our abilities and motivations when we reach adulthood stem from nonmonetary influences such as genetics, in-utero developments, our parents’ habits and behaviors, and peers. Also, there are diminishing returns to money; beyond a certain point, more parental income probably helps only a little, if at all.
Yet the graph suggests a large impact. Apart from data concerns, is there any reason to question this? I think so. First, let’s set aside the low- and middle-income countries (Argentina, Brazil, Chile, China, Pakistan, Peru, Singapore). Mobility processes in these countries may or may not be comparable to those in the rich nations. Next, notice that inhabiting the lower-left corner of the chart are the four Nordic nations: Denmark, Finland, Norway, and Sweden. These countries have been providing affordable high-quality early education to a substantial portion of children age 1 to 5 for roughly a generation. James Heckman and Gøsta Esping-Andersen, among others, have argued that early education is perhaps the single most valuable thing a society can do to equalize opportunity. These countries also feature late tracking in elementary and secondary schools and heavy subsidies to ensure college is affordable for all. These public services, rather than low income inequality, might be the chief reason the Nordic countries have such high intergenerational mobility.
What would that imply for the cross-country association between income inequality and intergenerational mobility? As the following chart shows, if we leave out the Nordic nations the association is still there, but the countries are widely dispersed around the line, suggesting weaker grounds for confidence that the association is a strong one. (For the statistically inclined, the r-squared is .47 with the Nordics included and .16 without them.)
Is it possible, then, for a country to have high income inequality but also low inequality of opportunity? John Quiggin is skeptical. He suggests the UK experience has debunked this “third way” notion. I’m not so sure. Imagine a rich nation with America’s income inequality and Nordic public services: affordable high-quality early education, K-12 schooling with late tracking and equal funding, and widespread access to good-quality universities. And perhaps also comprehensive prenatal care. Would its opportunity (mobility) structure look more like America’s or more like Sweden’s?
But, some will respond, you can’t get those services if income inequality is high. The rich will block the heavy taxation needed to fund them. Maybe. But income inequality has been rising in Sweden. In fact, in the late 1990s and mid 2000s the top 1%’s share of income (including capital gains) in Sweden was about the same as in the 1970s United States (see figure 7 in this paper by Atkinson, Piketty, and Saez). So far this hasn’t undermined Swedish taxation, though it’s probably too soon to draw any firm conclusions.
Suppose income inequality continues to rise in Sweden but its public services hold up. Will Sweden’s intergenerational mobility a few decades from now look like ours does today? I’d predict no. I suspect opportunity-enhancing programs can overcome a good bit of the harm done by income inequality.
That’s not to say we shouldn’t also try to reduce income inequality. I think we should. The point is that if we want to reduce inequality of opportunity, reducing income inequality isn’t the only way, and perhaps not even the best way, to do it.