In an unforgiving market, many low-cost "balanced" mutual funds split 60/40 between stocks and bonds lost 22 percent or more of their value last year, shriveling the 401(k) account balances of even well-diversified workers.

Those heavily invested in stock funds - or the single, sinking stock of their employer - lost even more. Many near retirement age will have to keep working for years.

In response, calls have intensified for changes in these employer-sponsored retirement plans, including proposals for the government to guarantee minimum investment returns.

I don't take sides on matters of public policy. I do believe it's a copout to blame any 401(k) plan shortcomings for our mistakes (or inactions) in saving for retirement.

Workers with access to a 401(k) plan decide whether to participate, how much to contribute up to a legal limit and what investments to pick among those offered. Employees, not employers, bear the investment risk.

When stocks soared in the late 1990s, few people paid much attention to valid criticisms of 401(k)s, including often opaque fees. That changed in 2008, just as new Department of Labor rules went into effect.

Under these rules, employees who don't "opt out" can be automatically enrolled in 401(k)s and their contributions invested in diversified portfolios of stocks and bonds. Before, if the employee made no investment choice, contributions would go into less risky but historically low-returning money market or stable-value funds. Continued...