Are tax incentives driving the shift from wages to business profits?
Core argument: Labor share fell 9 pts from 64% (2000) to 55% (2025), with tax policy driving one-third of the 1978–2017 decline.
The corporate-sector labor share was 63% in 1978, fluctuated modestly through the 1980s and 1990s, and still stood near 64% in 2000. Then it fell to 58% in 2017 and 55% in 2025. Change of label pulls down the measured labor share because the national accounts count S corporation profit as capital income. When we add these recharacterized wages back into the labor income bucket, then the corporate labor share in 2017 is about 0.9 percentage points higher. In addition, many firms have left the corporate sector and reorganized as partnerships. Partnership profit has grown from 13% of all business profit in 1980 to 35% today. These partnerships have labor shares more than 10 percentage points higher than the corporate firms left behind. As these high-labor-share businesses left, the corporate sector that remained looked more capital-heavy than it used to. When we treat the partnership activity that migrated out since 1986 as if it had stayed in corporate form, the 2017 labor share is another 0.7 percentage points higher. These two corrections together are worth about 1.6 percentage points. The headline decline from 1978 to 2017 was 5 points. Our adjusted decline is 3.4. Thus, the tax code accounts for roughly a third of the decline.

