Cuts to Corporate Welfare

According to a list compiled by Paul Buchheit in 2013, we have the following:
1) According to the Cato institute in 2012, there are $100 billion in corporate subsidies, including fossil fuel subsidies
2) According to a Bloomberg article in 2013, referring to an IMF report, banks get $83 billion in interest rate subsidies
3) According to a GAO report Buchheit references, there are $180 billion in corporate tax expenditures
4) According to a PIRG report from 2013, off-shore tax havens cost the Treasury $150 billion per year.

It may be that some of these are desirable, and some may be harder to access than others. We didn't even include everything Buchheit refers to, such as local subsidies. But all together, these four tax changes alone would yield about $500 billion per year.