Image copyrightGETTY IMAGES

There is, to use the great cliche, an elephant in the room.

The room is globalisation, the increasing international economic integration we have lived through over the last few decades.

The elephant is what that development has arguably done to the distribution of income.

Why an elephant?

Because there’s a graph showing what has happened that looks like one (especially if you join the dots up carefully and add in some ears, eyes and legs).

Image copyrightTWITTER

It shows what has happened to incomes across the global income distribution in the 20 years up to 2008.

Understanding the elephant

The horizontal axis shows the position in that distribution. The fifth dot, for example, is the 25th percentile. If you ranked everybody…