During the early 1980s, earnings inequality in the U.S. labor market rose relatively uniformly throughout the wage distribution. But this uniformity gave way to a significant divergence starting in 1987, with upper-tail (90/50) inequality rising steadily and lower tail (50/10) inequality either flattening or compressing for the next 16 years (1987 to 2003).
Rising Wage Inequality: The Role of Composition and PricesDavid H. Autor, Lawrence F. Katz, Melissa Kearney ,
NBER Working Paper No. 11628