The Myth that Growing Consumption Inequality is a Myth

Kevin Hassett and Aparna Mathur argue that consumption inequality has not increased along with income inequality. That's not what recent research says, but before getting to that, here's their argument:

Consumption and the Myths of Inequality, by Kevin Hassett and Aparna Mathur, Commentary, WSJ: In multiple campaign speeches over the past week, President Obama has emphasized a theme central to Democratic campaigns across the country this year: inequality. ... To be sure, there are studies of income inequality—most prominently by Thomas Piketty of the Paris School of Economics and Emmanuel Saez of the University of California at Berkeley—that report that the share of income of the wealthiest Americans has grown over the past few decades while the share of income at the bottom has not. The studies have problems. Some omit worker compensation in the form of benefits. And economist Alan Reynolds has noted that changes to U.S. tax rules cause more income to be reported at the top and less at the bottom. But even if the studies are accepted at face value, as a read on the evolution of inequality, they leave out too much.

Let me break in here. Here's what Piketty and Saez say about Reynold's work:

In his December 14 article, “The Top 1% … of What?”, Alan Reynolds casts doubts on the interpretation of our results showing that the share of income going to the top 1% families has doubled from 8% in 1980 to 16% in 2004. In this response, we want to outline why his critiques do not invalidate our findings and contain serious misunderstandings on our academic work. ...

Back to Hassett and Mathur

Another way to look at people's standard of living over time is by their consumption. Consumption is an even more relevant metric of overall welfare than pre-tax cash income, and it will be set by consumers with an eye on their lifetime incomes. Economists, including Dirk Krueger and Fabrizio Perri of the University of Pennsylvania, have begun to explore consumption patterns, which show a different picture than research on income.

Let me break in again and deal with the Krueger and Perri Krueger and Perri (2006) paper, which followed the related work by Slesnick (2001):

Has Consumption Inequality Mirrored Income Inequality?: This paper by Mark Aguiar and Mark Bils finds that "consumption inequality has closely tracked income inequality over the period 1980-2007":

Has Consumption Inequality Mirrored Income Inequality?, by Mark A. Aguiar and Mark Bils, NBER Working Paper No. 16807, February 2011: Abstract We revisit to what extent the increase in income inequality over the last 30 years has been mirrored by consumption inequality. We do so by constructing two alternative measures of consumption expenditure, using data from the Consumer Expenditure Survey (CE). We first use reports of active savings and after tax income to construct the measure of consumption implied by the budget constraint. We find that the consumption inequality implied by savings behavior largely tracks income inequality between 1980 and 2007. Second, we use a demand system to correct for systematic measurement error in the CE's expenditure data. ...This second exercise indicates that consumption inequality has closely tracked income inequality over the period 1980-2007. Both of our measures show a significantly greater increase in consumption inequality than what is obtained from the CE's total household expenditure data directly.

Why is this important? (see also "Is Consumption the Grail for Inequality Skeptics?"):

An influential paper by Krueger and Perri (2006), building on related work by Slesnick (2001), uses the CE to argue that consumption inequality has not kept pace with income inequality.

And these results have been used by some -- e.g. those who fear corrective action such as an increase in the progressivity of taxes -- to argue that the inequality problem is not as large as figures on income inequality alone suggest. But the bottom line of this paper is that:

The ... increase in consumption inequality has been large and of a similar magnitude as the observed change in income inequality.

So they are citing what is now dated work. They either don't know about the more recent work, or simply chose to ignore it because it doesn't say what they need it to say.

Okay, back to Hassett and Mathur once again. They go on to cite their own work -- more on that below. One thing to note, however, is that the recent research in this area says the data they use must be corrected for measurement error or you are likely to find the (erroneous) results they find. As far as I can tell, the data are not corrected:

Our recent study, "A New Measure of Consumption Inequality," found that the consumption gap across income groups has remained remarkably stable over time. ...

While this stability is something to applaud, surely more important are the real gains in consumption by income groups over the past decade. From 2000 to 2010, consumption has climbed 14% for individuals in the bottom fifth of households, 6% for individuals in the middle fifth, and 14.3% for individuals in the top fifth when we account for changes in U.S. population and the size of households. This despite the dire economy at the end of the decade.

Should we trust this research? First of all this is Kevin Hassett. How much do you trust the work once you know that? Second, it's on the WSJ editorial page. How much does that reduce your trust? I'd hope the answer is "quite a bit." Third, big red flags when researchers cherry pick start and/or end dates. Fourth, as already noted, recent research shows that the no growth in consumption inequality result is due to measurement error in the CES data. When the data are corrected, consumption inequality mirrors income inequality. They don't say a word about correcting the data.

Next, we get the "but they have cell phones!" argument:

Yet the access of low-income Americans—those earning less than $20,000 in real 2009 dollars—to devices that are part of the "good life" has increased. The percentage of low-income households with a computer rose... Appliances? The percentage of low-income homes with air-conditioning equipment..., dishwashers..., a washing machine..., a clothes dryer..., [and] microwave ovens... grew... Fully 75.5% of low-income Americans now have a cell phone, and over a quarter of those have access to the Internet through their phones.

Before turning to their conclusion, let me note more new research in this area from a post earlier this year, But They Have TVs and Cell Phones!, emphasizing the measurement error problem:

Consumption Inequality Has Risen About As Fast As Income Inequality, by Matthew Yglesias: Going back a few years one thing you used to hear about America's high and rising level of income inequality is that it wasn't so bad because there wasn't nearly as much inequality of consumption. This story started to fall apart when it turned out that ever-higher levels of private indebtedness were unsustainable (nobody could have predicted...) but Orazio Attanasio, Erik Hurst, and Luigi Pistaferri report in a new NBER working paper "The Evolution of Income, Consumption, and Leisure Inequality in The US, 1980-2010" that the apparently modest increase in consumption inequality is actually a statistical error.

They say that the Consumer Expenditure Survey data from which the old-school finding is drawn is plagued by non-classical measurement error and adopt four different approaches to measuring consumption inequality that shouldn't be hit by the same problem. All four alternatives point in the same direction: "consumption inequality within the U.S. between 1980 and 2010 has increased by nearly the same amount as income inequality."

Here's Hassett and Mathur's ending:

It is true that the growth of the safety net has contributed to massive government deficits—and a larger government that likely undermines economic growth and job creation. It is an open question whether the nation will be able to reshape the net in order to sustain it, but reshape it we must. ...

After arguing (wrongly) that consumption has kept pace with income, they say it's only because of the deficit -- but it's not sustainable. So suck it up middle class America, consumption inequality has increased despite the claims of denialists like Hassett, and if they get their way and reduce the social safety net, it will only get worse.

Hassett and company denied that income inequality was growing for years (notice their attempt to do just that in the first paragraph by citing discredited research from Alan Reynolds), then when the evidence made it absolutely clear they were wrong (surprise!), they switched to consumption inequality. Recent evidence says they're wrong about that too.