One way to look at those numbers: Companies "punish" poor performers at more than twice the rate they reward top performers. The worst get dinged 33 percent of their target bonus, while the best can only expect 15 percent above target.
McLellan sees it the other way around, however.
"This is saying managers are feeling the need to give something to everybody," she said. "In some cases, managers are feeling that the bonus is not related to performance but part of what people should be entitled to."
That humane-sounding approach throws a big monkey wrench into the big idea behind bonuses, which is part of the reason corporations are now complaining that they are having trouble holding on to their best employees.
While the economy is still growing in only fits and starts, and wages overall are barely rising, leverage has changed for top talent, McLellan said. The Towers Watson survey found that 40 percent of firms said turnover is rising, and 52 percent said they are having difficulty retaining "critical-skill" employees, compared to 41 percent last year.
"We are starting to see mobility in certain categories," Abosch said. "People with a specialized skill set, like engineers, financial auditors, analysts."
You'd think the solution to the problem of "talent mobility" would be relatively easy to solve — more pay.
"It's not that complicated, but it's hard to put into practice," McLellan said. Managers are not necessarily comfortable picking winners and losers on an annual basis. "And if your bonuses are not funding at 100 percent, it puts managers into more difficult discussions."