U.S. workers may be starting to become more optimistic about the economy.

Principal Financial Group Inc., Des Moines, Iowa, has published that conclusion in a summary of results from a survey of about 1,200 employees of small to midsize businesses and about 500 retirees.

Only 18% of workers surveyed this quarter said they expect the economy to get worse by the end of year, a drop from 24% in the first quarter.

Principal found that 27% of the workers and 31% of the retirees think the economy will get better by the end of the year.

But 41% predicted it will take 2 to 5 years to recover the retirement account balances they had at the start of January 2008. Another 15% said they think it will take 6 to 10 years to recover, and 3% said they think the totals will never recover, Principal found.

About 14% of the workers said they had increased the amount they are saving for retirement over the past 6 months. The percentage saying they are not saving for retirement has fallen to 16%, from 20%.

The percentage who say current economic conditions have persuaded them to postpone their anticipated retirement date has increased to 13%, from 10%.