The Berlin Wall’s fall was a unique moment in geopolitical history, ushering in an era of unipolarity as the United States became the world’s hegemon. But it also heralded an unprecedented economic phenomenon: convergence. As early as the fifteenth century, formerly prosperous societies from Mesoamerica to China suffered reversals of fortune, falling—or being pushed—behind the West. With the advent of the Industrial Revolution, growth rates in rich and poor nations diverged even further.