It’s hard to investigate the causes of income inequality without looking at the sources of income. In turns out that, in the U.S. at least but probably also in other developed countries, the majority of a population gets almost all of its income from wages, while people at the top of the income distribution get most of it from capital gains and dividends.
Dividends are payments made by a corporation to its shareholder members, usually a portion of corporate profits. Capital gains are profits that result from investments into a capital asset, such as stocks, bonds or real estate, which exceeds the purchase price. A capital gain is the difference between a higher selling price and a lower purchase price, resulting in a financial gain for the investor.
Given these differences in the sources of income, income inequality will rise if incomes from capital gains and dividends rise more rapidly than wage incomes, perhaps because taxes on the former are cut. And indeed, most of the recent increase in the Gini score for the US (higher Gini numbers imply a less equal distribution) comes from higher capital gains and dividends and from lower taxes for high earners (lower taxes not only on capital gains, by the way; many taxes have become less progressive in the U.S.).
This cause of income inequality suggest a problem that goes deeper than inequality:
I think a lot of people sense that there’s something unsettling about this shift from labor income to capital incomes. It seems endemic of a society that devalues work while providing outsized rewards for speculation and asset accumulation. (source)
More posts in this series are here.