Following in my illustrious footsteps as an Econ​o​mist​.com guest blogger, Brookings senior fellow Jason Furman writes thusly of rising income inequality:

According to the Congressional Budget Office’s income inequality data, the top 1 percent of households have seen their incomes go up by 7 percent and the bottom 80 percent have seen their income shares go down by 7 percent. In total that is a $664 billion increase in inequality, representing $7,000 for each household in the bottom 80 percent and nearly $600,000 for each household in the top 1 percent.


That number motivates a Hamilton Project tax strategy paper co-authored by Larry Summers, Jason Bordoff and myself that is being released today.


It is far from obvious what has caused the change; in just the last month alone the National Bureau of Economic Research has released three working papers with divergent explanations: a reduction in the bargaining power of workers, an increased reward for skills and worker productivity, and the destruction of good jobs by trade.


Regardless of the cause of rising inequality, lefties, utilitarians, Rawlsians and anyone with a deep-seated reverence for markets and the capitalist system should all be concerned. As Alan Greenspan memorably stated, “income inequality is where the capitalist system is most vulnerable. You can’t have the capitalist system if an increasing number of people think it is unjust.”

Well, I consider myself a sort of Rawlsian (a Rawlsekian!) with a deep-seated reverence for markets and the capitalist system. Should I be concerned? I agree with the sainted Greenspan that capitalism cannot survive a widespread conviction that it is unjust. And I agree that income inequality is one of those things that some thinkers like wheel out to try to convince us that capitalism is unjust, at least around the edges, in order to build popular support for such things as more steeply “progressive taxes combined with expanded benefits like health insurance,” like Furman wants. But I’m not so worried by rising income inequality as I am by Furman’s facile slide from income inequality numbers, which are meaningless by themselves, to the possibility of a crisis of legitimacy.


It is worth repeatedly and forcefully emphasizing that income inequality may or may not be symptomatic of injustice. The three hypotheses for rising inequality Furman mentions are perfectly consistent with advances in justice. And if they are generating income inequality, then it may vindicate capitalism. For example, the loss of jobs, a decrease in wages, or a decrease in bargaining power for some workers may be a consequence of lifting coercive restrictions on voluntary exchange across borders — restrictions that are themselves a form of injustice. Furman himself notes that protectionist policies could decrease inequality, though he advises against them, and rightly so, since they are unjust. But if protectionist policies are lifted, and inequality increases, that uptick in inequality is a side-effect of justice, not a symptom of injustice.


Inequality may reflect real injustice in our culture and institutions, and some portion of it probably does. But then our focus ought to be on rooting out those injustices, not papering them over with confiscatory redistribution which, in the absence of a reason to do it other than arbitrarily reducing measured inequality, is straightforwardly immoral.


Let’s set aside the matter of the intelligibility of “shares” of “national income” as a subject of justice for another time.