The workers that employers have left may be more productive, but they are also angrier.

The percentage of U.S. employers who say they feel a very strong sense of loyalty to their employees has held steady at 57%, and the percentage who say workplace satisfaction is high increased to 44% in 2010, from 43% in 2008,.

But the percentage of employees who say they feel a very strong sense of loyalty to their employers has fallen to 47%, from 59% in 2008, and the percentage who say their companies have a very strong sense of loyalty to them has fallen to 33%, from 41%.

About 36% of current employees say they would like to be working somewhere else by the end of the year.

Researchers commissioned by a unit of MetLife Inc., New York (NYSE:MET), have published those figures in a summary of results from one survey of 1,508 benefits decisionmakers at U.S. employers with at least 2 employees and a second survey of 1,412 full-time U.S. employees ages 21 and older at companies with at least 2 employees.

A few years ago, the job market was hot, and employers were focusing on keeping good employees. Now, employers are telling MetLife that controlling health and welfare benefits costs is a more pressing concern than employee retention.

About 39% of the employers told MetLife they have increased employee productivity in the past 12 months.

“But these productivity gains were not viewed as favorably by employees, and they could begin to wane if employees head out the door once the economy recovers,” the researchers note.

About 40% of the employees surveyed said they have been working harder in the past 12 months, and 25% said they feel even less secure in their jobs this year than they did a year ago, the researchers say.

In Wisconsin, a battle between state employees and a budget-cutting governor nearly shut down the state government, as the governor has been trying to tackle health and pension costs by eliminating collective bargaining.

Building a strong benefits program can help increase worker loyalty, but that may be more challenging in the next few years, as employers decide whether to drop health coverage, pay a penalty and have workers buy coverage through the new health insurance exchanges, or continue to “play” and offer traditional group health benefits, the researchers say.

As many employers deemphasize their role as the group health plan sponsor, other benefits, such as life insurance, disability insurance and retirement benefits, may get more attention, the researchers say.

Other MetLife benefits survey coverage from National Underwriter Life & Health: