Economic Research: How Increasing Income Inequality Is Dampening U.S. Economic Growth, And Possible Ways To Change The Tide When Ends Don't Meet A few factors help explain the concentration within so-called "market income," which consists of labor income (wages and salaries, plus employer-paid benefits), capital income (excluding capital gains), business income, capital gains, and other income--all before government taxes and transfers (see Glossary for full definition). The first reason is relatively simple: All these sources of income are less evenly distributed now than a few decades ago. In 1979, the bottom four-fifths of the income spectrum earned nearly 60% of total labor income, about 33% of income from capital and business, and about 8% from capital gains. By 2007, the bottom four-fifths share of labor income had dropped to less than 50%, income from capital and business had decreased to 20%, and capital gains fell to about 5%. In other words, all sources of income were less evenly distributed in 2007 than in 1979 (9). Some point to the "superstar status" effect, with professional athletes and movie actors enjoying astronomical increases in earnings in the past few decades, helped by technological innovation that broadened their reach across global markets and a "winner take all" phenomenon. Another "superstar" is the "super managers." Piketty argues that the "primary reason for increased income inequality in recent decades is the rise of the super managers in both the financial and nonfinancial sectors," finding that about 70% of the increase in income going to the top 0.1% from 1979 to 2005 came from increasing pay for those professionals (10). Other studies show that, since the 1990s, deregulation, corporate governance, and a greater reliance on equity options in executive compensation contributed to the compensation gap (11). Another explanation of market income concentration is technological innovation. This phenomenon boosted the value of high-skill wo