One of the lessons of Branko Milanovic’s work on global inequality has been the realization that location, and perhaps more pertinently, nationality, is a more important explanation of how well and badly off people are than class is. Citizens of wealthy countries enjoy a “citizenship premium” over the inhabitants of poor ones that exists because they have access to labour markets and welfare systems that their fellow humans largely do not. Of course, there’s a sense in which this global difference also represents a class difference, with many of the workers simply located elsewhere while the residual “proletarians” of the wealthy world enjoy a contradictory class location (to repurpose a term from Erik Olin Wright). While it might be that world GDP would increase dramatically if barriers to movement were removed, as some economists have claimed, the relative position of the rich world poor depends upon those barriers being in place. Or to put it another way, free movement could make many poor people much better off and might not make the rich world poor any worse off in absolute terms, but it would erode their relative advantage. And people, however misguidedly care about their relative advantage.
What kind of politics would we expect to have in rich countries in a world like ours, if people were fully cognizant of this citizenship premium? I suspect the answer is that we would expect to see stronger nationalist movements seeking to preserve the advantage of members of the national collective over outsiders and correspondingly weaker parties based on class disadvantage within those countries. Which is, in fact, the tendency we do see in many European countries where traditional social democracy is struggling badly at the moment. In those same countries we might also expect to see some voters who are unthreatened by freer movement, or by the rise of new powers in the world, being more open to a more cosmopolitan politics and more preoccupied by other issues such as climate change and the environment. And this is, in fact, what we do see.