How productive are owner-managers?

We find that the average premature death of a million-dollar-earning owner causes an 82% decline in firm profits.

And:

The data reveal a striking world of business owners who prevail at the top of the income distribution.  We find that most private business profits reflect the return to owner human capital.  Overall, the top earners are predominantly working rich, and the majority of top income accrues to the human capital of wage earners and entrepreneurs, not idle owners of financial and physical capital.

That is from Matthew Smith, Danny Yagan, Owen M. Zidar, and Eric Zwick, “Capitalists in the Twenty-First Century,” a new research paper.