Capital in the Twenty-First Century by Thomas Piketty, 2014, Excerpts
Foreign possessions became important in the period 1750-1800. It was the nineteenth century that British subjects began to acquire considerable assets in the rest of the world, in amounts previously unknown and never surpassed to this day. By the eve of WWI, Britain had assembled the world’s preeminent colonial empire and owned foreign assets. France was the second most important colonial power.
By the turn of the twentieth century, capital invested abroad was yielding around 5 percent a year in dividends, interest, and rent. A fairly significant social group was able to live off this boon. The rest of world worked to increase consumption by the colonial powers and at the same time became more and more indebted to those same powers.