Summary of The Great Leveler

The “Four Horsemen”

In 2010, it took the combined wealth of 388 billionaires to match the holdings of the lower-half billions. By 2015, that had shifted: 62 megabillionaires owned as much wealth as the 3.5 billion people on the bottom half of the global income scale. The decades after World War II were a golden age for income equality. The economies of the developed world hit record levels of equality sometime in the 1970s or early 1980s. By the mid-1980s, wealth in North America, Europe and Asia had concentrated into fewer hands. Since 1983, equality has steadily declined. By 2012, the US economy was as unequal as it was in 1929.

A close study of history reveals that income inequality often follows desirable societal developments and economic advances. For instance, primitive hunter-gatherers had little wealth and thus little inequality. The emergence of agrarian societies and land ownership led to the evolution of cereal crops and accelerated the accumulation of wealth. Grains’ long shelf lives enabled landowners to amass riches.

Rare episodes of flattening inequality resulted from large-scale disasters. These upheavals fall under the categories...