Conservative economist Marty Feldstein has proposed limiting the value of tax expenditures to 2 percent of income.

FORBES: Let's Bribe Taxpayers To Give Up Tax Breaks

President Obama proposed a different way to raise taxes by limiting the value of all itemized deductions and some other preferences to 28 percent.

FORBES: Senate Budget's Bad Math: Axing Tax Breaks For Rich, Big Business Isn't Enough

He would let the two top brackets, now 33% and 35%, revert to 36% and 39.6%, which is where they were until 2001, limiting the value of deductions available to top earners.

ECONOMIST: Taxes, spending and the deficit

Although the practice was not prohibited, it created a massive market for gambling on companies' credit worthiness without limiting those bets to the value of the underlying obligations.

FORBES: Intelligent Investing Briefing Book

Barclays said on July 5 that it attributed this allocation decision to the heightened uncertainty in the euro area and the potential for volatility in currency markets, limiting the upside potential in local currency bonds as they lose value compared to the dollar.

FORBES: For Emerging Markets, The Flow Is Your Friend

Jonathan Ostry, an economist at the IMF, reckons there is a theoretical case for limiting capital inflows to prevent a surge in currencies above fair value.

ECONOMIST: Free exchange