Clearly there are issues with the way we measure income inequality in the US. But any way that I can measure it, I still see that there seems to be an actual increase in it. This is NOT a post on whether you should be concerned about that. It is, rather, a simple methodological post. People have all kinds of pet stories for why inequality seems to be increasing. And I am almost sure there many “correct” reasons – I favor demographic explanations, others favor “skill-biased” technical change, others favor class-struggle stories, other stories exist too. But, whatever your story is, you should understand that the trends in inequality are not unique to the United States.
Yes, measured Gini data indicate inequality is higher in America than in many other places, but look at the data for almost any OECD country over the past 40 years. With few exceptions there have been sizeable increases in inequality in those places. Here is a database that allows you to track income shares among the top across a variety of countries and over time. Whatever your story is about the U.S., it is a pretty good starting point to ask yourself whether you believe the same thing is happening in other countries. It’s surely possible that different factors cause inequality in all the OECD countries, but the trends are not unique to the USA.
And yes, there are some exceptions in the data. Check out France for example.