NEW YORK (CNNMoney.com) – By now everyone knows American workers aren't saving enough for retirement.

But part of the reason may be because the incentives to save – including tax breaks and ease of access to accounts – are not as effective or widespread as they could be, say some retirement experts.

There certainly have been some improvements in the 401(k) arena, which is the major savings vehicle for Americans who save for retirement.

Thanks to the introduction of automatic enrollment, for example, the number of workers with one year of tenure participating in a 401(k) is up 6 percentage points to 36 percent from a year earlier, according to a study released Tuesday by Hewitt Associates.

Overall, participation rates in companies offering automatic enrollment is 14 percentage points higher than participation rates at companies that don't, Hewitt found. And in particular auto enrollment has brought more of those least likely to participate historically – namely, young, low-income or low-tenured employees -- into the fold.

But there are still great discrepancies in participation and savings rates between high-income workers and everyone else.

At a pension conference cosponsored by the AARP and the Employee Benefit Research Institute on Monday, pension experts pointed to two areas that need improvement if Americans are going to save more: the tax breaks offered savers and the availability of automatic savings options for workers whose employers don't sponsor a retirement plan.

"Our tax incentives are upside down," said Peter Orszag, a senior fellow at the Brookings Institution.

Currently, a worker's contribution to a 401(k) or deductible IRA reduces his taxable income. As a result, the higher your tax bracket, the higher your tax savings.

Hence, higher income workers tend to benefit more from this incentive than lower income workers. For example, a saver in the 35 percent tax bracket reduces his taxes by 35 cents for every dollar he contributes, whereas a saver in the 15 percent bracket only reduces his taxes by 15 cents for that same dollar.

Orszag proposes changing the tax incentive so it's the same for everyone. Instead of getting a deduction for contributions, savers would get a matching contribution from the government.

The match would be 30 cents on the dollar up to either 10 percent of gross income or $20,000 for 401(k)s and $5,000 for IRAs, whichever is less.

For many low- and middle-income taxpayers, that would provide an increased financial benefit. High-income earners, however, would see a decline in their benefit.

Orszag in a paper published last month notes that a family making $60,000 in the 15 percent tax bracket currently reduces their taxes by $750 when they make a $5,000 contribution. Under the matching system, they'd get a $1,275 match on a $5,000 contribution, for a total investment of $6,275, on top of any employer match.

A family making $500,000 in the 35 percent bracket now reduces their taxes by $7,000 on a $13,000 contribution. Under the matching system, they'd receive $3,900, for a total investment of $16,900, on top of any employer match.

Under this proposal, the employer match would be treated as taxable income to the worker. Currently it's tax free.

The cost to the government in forfeited tax revenue, Orszag said, would be about the same as the cost of the deductions offered today.

Another factor dissuading lower income workers from contributing, Orszag noted, are the asset-level tests used to determine eligibility for anti-poverty programs such as food stamps and Medicaid.

The asset tests were set when defined benefit pensions were the norm, he noted, so they don't necessarily exempt 401(k) or IRA savings when determining a family's eligibility for aid. Unless the asset tests are reassessed, he said, saving for retirement will continue to disqualify some workers from getting aid.

A number of speakers at the conference focused on the 70-million-plus workers who are not enrolled in any workplace retirement plan. Often it's because their employers don't offer one, but it also may be because they are not eligible for their employer's plan or are working as independent consultants.

J. Mark Iwry, a senior fellow at the Brookings Institution, proposed that such workers be given access to an automatic IRA into which they are allowed to invest small amounts from every paycheck.

The only burden on employers would be to inform workers of the savings option and to facilitate the automatic payroll deduction. In return they would receive a tax credit, but not as large a credit as if they sponsored their own 401(k).

To entice workers to save, Iwry proposes that the financial institutions that provide the direct-deposit IRAs offer a matching contribution, in exchange for which they would receive a tax credit.

Except for workplace savings, the retirement asset picture likely would be dismal. And given that few exercise their option to open an IRA, the auto IRA for workers, like auto enrollment for 401(k) participants, just might push the savings rate higher.

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