If investors focused on the economic cost of losses relative to the benefit of gains, they would likely change their perspective on performance evaluation.

FORBES: Peace Of Mind Performance In Stocks

In the recent case of Chicago, the teachers union resisted the notion that 30 percent of their evaluation should be based on student performance.

FORBES: Why Rahm Was Right To Fight For Kids

The foundation and others have estimated that it could cost between 1.5% and 2% of the overall budget for teacher compensation and benefits to implement a feedback and evaluation system based on multiple measures of teaching performance.

CNN: Bill Gates: Invest in better teaching