The economy is outright preventing or dissuading many American workers from saving for retirement, according to an analysis of U.S. Census Bureau data by the Employee Benefit Research Institute.

Among workers most likely to have benefits, that is, full-time workers between the ages of 21 and 64, 54.4% participated in a company-sponsored retirement plan in 2009, down form 60.4% in 1999.

Among all workers, including those not offered a retirement plan at work, 39.6% participated in a retirement plan in 2009, down from a high of 44.4% in 2000.

And the number of employers sponsoring retirement plans dropped to 61.8% last year, from a high of 69.4% in 1999.

EBRI expects retirement plan participation to fall even more this year, since unemployment remains high and many private sector employers have frozen their traditional defined benefit plans.

“This trend has important implications for workers, since having more opportunities to participate in an employment-based retirement plan greatly increased the amount of money a retiree is likely to have in retirement,” said EBRI Senior Research Associate Craig Copeland.

EBRI’s report, “Employment-Based Retirement Plan Participation” Geographic Differences and Trends,” which is available online, also found that participation increases with age. Among those between 55 and 64, 61.2% participated in a retirement plan, whereas only 30.6% of those between the ages of 21 and 24 participated.

EBRI also discovered that Hispanic wage and salary workers were significantly less likely than white and black workers to participate in a retirement plan, and people in the South, West and Southwest had the lowest participation levels. The Midwest and Northeast had the highest participation levels.