The youngest workers, aged 21-29, do the worst job, with only 11 percent saving their income for retirement, while those aged 45-64 do the best, with 26 percent lower income earners saving for retirement and 49 percent of higher earners doing so. Younger workers more frequently put the money towards their own liquidity (39 percent) or home purchases or education costs (24 percent) 

As a result, older or higher-paid employees are more likely to have the luxury of participating in an employer-based retirement plan; younger employees would rather receive better pay than better retirement benefits.

And the folks who take part in retirement plans are also a privileged portion of the working public, tending to be older, better paid and in full-time positions for at least a year or more. Younger, lower-paid, temporary employment-oriented workers find themselves excluded from most formal retirement savings programs.

The spin-off to that finding, researchers suggest, is that it will continue to be crucially important to maintain Social Security as long and as fully as possible, as it may be the only retirement funding assistance many low-income earners have in their latter years.

Those fortunate enough to work in jobs with retirement benefits as part of their compensation also tend to fall into two groups, the study says: Those would like to participate but are turned off because of the tax penalties and restrictions over early access to their own retirement savings, and those who see those restrictions as being beneficial to their savings hygiene. The former, the study indicates, would mostly rather receive cash as compensation than retirement benefits and cash.

Employees at small companies – with 10 employees or less – are also the least likely to be offered any form of retirement plan, with only 18 percent telling researchers they had access to retirement benefits, versus 68 percent of those working for companies with 1,000 or more workers.

If employee sponsored plans are offered, workers universally opt to take part, with participation levels as high as 80 percent, regardless of the size of the business.

All totaled, some 78.7 million workers in the U.S. are employed by companies without sponsored retirement benefits plans, predominantly in the private sector (52 million) and self-employed categories.

Of those private sector workers, 21 million are part-time or part-year workers, unable to qualify for benefits. Some 23.5 million are full-time workers but earn $45,000 a year or less; the lower the pay, the less likely they are to have the ability to save for retirement.

In the end, the researchers suggest that the private sector pension and retirement savings system can and should be improved, though for the most part, employees who are most likely to take part in a retirement system are already doing so.