According to the IRI study, a 30-year-old who manages to put away 7 percent of his pay and gets an employer match of 3 percent will be better off than if he'd waited until age 35 before he started to save. That's because by that point, he'd have to save 16.5 percent (13.5 percent of salary plus that 3 percent employer match) to end up with the same amount of money.

IRI's study concluded that the worker who started saving at 30 would have a retirement income of $22,467 (expressed in today's dollars) at age 65. And if they worked until age 70, that income would rise to $38,829 — higher by 72.8 percent than if he'd retired at 65.

On the flip side, should that same worker wait until age 35 to start saving, he would have to save more than 16 percent of his income each year to have the same amount he'd get if he'd started at age 30.

If he waits until age 40, the required savings would climb to more than 26 percent of annual income — not an easy task.

One particularly scary graph in the study shows the increase in percentage of salary that must be saved each year that saving is delayed past the age of 30 in order to match retirement income at age 65. If they wait until, say, age 42 to start saving, workers would have to put away 20 percent each year; by age 48, it's 30 percent per year.

That could easily be the scenario for a woman who has been out of the labor market raising children, with no income, who either returns to work or enters for the first time when the kids are grown. 

If by some mischance retirement savings start even later than that, the savings rate quickly becomes untenable. That could easily be the case with a couple whose main breadwinner has been put out of work by the Great Recession while the other spouse is now responsible for supporting the household, or for an individual whose retirement plan was wiped out either in the wake of the tech bubble or during the downturn.

Beginning to save for retirement at age 54 would necessitate a savings rate of more than 50 percent of income just to have that retirement income of $22,467. 

While IRI's projections are based on a 7 percent return on investments each year — an assumption that can be problematic — the numbers do show the advantage of saving early.

But, as IRI points out in the paper, "Unfortunately, most projections of future account balances, including those used in this paper, are based on investment return assumptions that … do not truly compound the way an interest-bearing security or savings account does."

In addition, the paper points out that the present value of expenditures in retirement has also increased exponentially. In 1984, the Bureau of Labor Statistics put average annual expenditures for someone in the 65-74 age group at $15,842. In 2013, that had gone up to $46,757, and when health care costs are factored in, retirees will need considerably more per year than that $22,467. 

In calculating the present value of expected expenditures — how much in retirement savings someone will need to finance 40 years of expenditures — the study shows that amount was approximately $300,000 in 1984. By 2013, it had risen to more than $700,000. The present value of Social Security benefits in 2013 was only $400,000 — leaving a large gap for workers to fund by savings. 

The bottom line? Saving early may not be the solution, but it does greatly improve the odds of having enough to live on in retirement.