Even if one doesn't consider environmental, social, governance (ESG) criteria in evaluating companies, it's useful to know which company CEOs are overpaid in comparison to the rest of the company, and in comparison to their peers. What if these CEOs were paid according to shareholder return? In many cases, their pay would be cut.

That's according to findings from the sixth annual report, "The 100 Most Overpaid CEOs of the S&P 500: Are Fund Managers Asleep at the Wheel?" published by As You Sow, a nonprofit organization focused on shareholder advocacy. The report's rankings are calculated on the assumption that executive pay should be closely linked to corporate performance.

The most overpaid CEOs "each had compensation that was at least $20 million higher than if their pay had been properly aligned with performance. Of these CEOs, one received compensation that was $200 million above what the performance of the company justified, another one was $100 million above what it should have been based on TSR, and two others more than $50 million higher," the report says.