As the chart from the Roine and Waldenström study shows, the share of income for the top 1% in these seven countries generally follows the same trend line. That means domestic policy can’t be the principal reason for the current spread between high earners and others. Since the 1980s, that spread has increased in nearly all seven countries. The U.S. and Sweden, countries with very different systems of redistribution, along with the U.K. and Canada show the largest increase in the share of income for the top 1%.
The main reasons for these increases are not hard to find. Adding a few hundred million Chinese and Indians to the world’s productive labor force after 1980 slowed the rise in income for workers all over the developed world. That’s the most important factor at work. The top 1% gain relatively because they are less affected by the hordes of newly productive workers.
But the top 1% have another advantage. Many of them have unique skills that are difficult to replicate. Our top earners include entrepreneurs, rock stars, professional athletes, surgeons and lawyers. Also included are the managers of large international corporations and, yes, bankers and financiers
via Allan Meltzer: A Look at the Global One Percent – WSJ.com.