Champernowne Model Estimates of Aggregate Concentration in the United States, 1931-2000

We estimate parametric Champernowne distribution functions for corporate assets in the United States to obtain continuous measures of aggregate concentration and corporate inequality. Our series on asset shares of the largest 200 and 500 non-financial firms show that concentration before World War II was the highest during the 20th century, and had been falling since the merger wave of the late 1960s. Inequality among the largest 200 corporations exhibited an inverse U-shaped trend, fluctuating before the 1960s and falling thereafter