From Executive Excess 2008:

The U.S. tax code currently is riddled with loopholes that allow top corporate and financial leaders to avoid paying their fair share of taxes. Still other loopholes allow corporations to claim unwarranted deductions for exorbitant executive pay. Ordinary taxpayers wind up picking up the bill. That’s why this report defines such loopholes as “subsidies for executive excess.”

Estimated Annual Cost to Taxpayers of the Five Most Direct Tax Subsidies for Excessive Executive Pay

1. Preferential capital gains treatment of carried interest $2,661,000,000
2. Unlimited deferred compensation $80,600,000
3. Offshore deferred compensation $2,086,000,000
4. Unlimited tax deductibility of executive pay $5,249,475,000
5. Stock option accounting double standard $10,000,000,000

Total $20,077,075,000