I frequently make the point that America’s tax system is more progressive than European tax systems.

But not because the United States imposes higher tax rates on upper-income households. Instead, the big difference is that lower-income and middle-class households in the United States face much lower tax burdens than their European counterparts.

In those columns, I sometimes assert that upper-income taxpayers in the U.S. face tax burdens that are comparable to rich taxpayers in Europe.

But I’ve never explicitly shown why that is the case. So that will be the focus of today’s column.

Let’s start with this chart showing that top income tax rates for New Yorkers and Californians are explicitly at European levels.

The chart comes from a Washington Post editorial. Here are some excerpts.

…residents of some of America’s wealthiest areas are already paying European income tax rates. …the top federal income tax rate of 37 percent only tells part of the story in most of the country. The state and local income tax in New York City, for example, tops out at 14.776 percent. That means rich people there pay a top marginal income tax rate of 51.776 percent. California cities don’t have income taxes, but the state’s top rate of 13.3 percent means the wealthy pay a top rate of 50.3 percent. …Jacking up the tax rate for the top bracket wouldn’t do much to tax the billionaires that the far-left wants to target. It would hit a bunch of small businesses, whose income passes through the individual tax code. And the top rates in two of the wealthiest Democratic-governed jurisdictions are at European levels already.

One obvious response to this data is to note that most upper-income Americans are lucky enough (or smart enough) not to live in New York and California.

So does that mean very successful Americans enjoy lower tax burdens than well-heeled Europeans?

That’s not clear. A big difference between rich people and the rest of us is that they get the vast majority of their income from business sources and investments.

So any comparison of relative tax burdens on upper-income taxpayers in America and Europe also should measure the extent of “double taxation” on both sides of the Atlantic Ocean. To be more specific, what is the cumulative effect of dividend taxes, capital gains taxes, death taxes, wealth taxes, etc?

And this, as illustrated by the chart, is an area where the United States unfortunately is worse than the European average.

To cite just one example, top capital gains rate in the United States is above 28 percent in the United States compared to an average of less than 18 percent in Europe.

The bottom line is that the top personal income tax rate is a bit lower in the United States but double taxation is a bit higher.

One policy conclusion, based on the latest research, is that both American politicians and European politicians are probably fleecing the rich at close to the long-run revenue-maximizing rates, but doing it in slightly different ways.

But both are taxing way above the growth-maximizing rate.