To the let's-cut-entitlements crowd, what's wrong with America is that seniors are living too high off the hog. With the cost of medical care still rising (though not as fast as it used to), the government is shelling out many more dollars per geezer (DPG) than it is per youngster (DPY). The solution, we're told, is to bring down DPG so we can boost DPY.We do indeed need to boost DPY. And we need to rein in medical costs by shifting away from the fee-for-service model of billing and paying. But as for changing the way we calculate cost-of-living adjustments for seniors to keep us from overpaying them -- an idea beloved of Bowles, Simpson, Republicans and, apparently, the White House -- this may not be such a hot idea, for one simple reason: An increasing number of seniors can't afford to retire.Nearly one in five Americans age 65 and over -- 18.5 percent -- were working in 2012, and that percentage has been rising steadily for nearly 30 years. In 1985, only 10.8 percent of Americans 65 and older were still on the job, and in 1995, that figure was 12.1 percent.The good news is that more seniors both can and want to work than in years past, as healthcare and medical science have extended their capabilities. A 2011 survey by the Society of Actuaries reported that 55 percent of working seniors said they had stayed employed because they wanted to stay active and involved. But the same survey showed that 51 percent were working because they needed the money.What advocates for reducing Social Security adjustments fail to consider is that corporate America's shift away from defined-benefit pensions to defined-contribution 401(k) plans -- or to no retirement plans at all -- has diminished seniors' non-Social Security income and made the very idea of retirement a far more risky prospect. Today, more than half of U.S. workers have no workplace retirement plan. Of those who do, just 35 percent still have defined-benefit pensions. The shift from traditional pensions to 401(k)s is one of the main reasons most seniors aren't able to set aside enough income to guarantee a secure retirement. A 2010 survey by the Federal Reserve found that the median amount saved through 401(k)s by households approaching retirement was $100,000 -- not nearly enough to support those households through retirement years, as seniors' life expectancy increases. And as most Americans' wages continue to stagnate or decline, their ability to direct more of their income to 401(k)s diminishes even more.With the eclipse of the defined-benefit pension, Social Security assumes an even greater role in the well-being of American seniors. But advocates of entitlement cuts don't even discuss the waning of other forms of retirement security.And it's not as if those employers are suffering. Just as U.S. businesses have been able to raise the share of corporate profits to a half-century high by reducing the share of their workers' wages to a half-century low, so, too, their ability to reduce pension payments has contributed not just to their profits but also to the $1.7 trillion in cash on which they are currently sitting.So here's a modest plan to enable seniors to retire when they wish, rather than having to work into their 70s and even beyond: Require employers to put a small percentage of their revenue, and a small percentage of their workers' wages, into a private, portable, defined-benefit pension plan. To offset the increased costs, transfer the costs of paying for workers' healthcare from employers and employees to the government, and pay for the increased costs to the government with the kind of value-added tax that most European nations levy.The odds of such a plan being enacted today, of course, are nil. But until we compensate for, or reverse, the abdication of corporate America from any major role in providing its workers with retirement security, we should lay off monkeying with Social Security to reduce the program's future payments.Harold Meyerson is editor-at-large of The American Prospect.