American workers have a problem saving for retirement, but it’s not getting fixed by higher limits on how much they can contribute to their 401(k) plans.

Those are the conclusions of a new study from the Center for Retirement Research at Boston College that looked at 401(k) contribution patterns of people both under and over the age of 50.

Researchers wanted to see how changes made by Congress in 2001 to tax-deferred contribution limits affected how much people contributed to their retirement plans. The group under the microscope, so to speak, included individuals aged 46–53, and the period considered fell between 1999 and 2005, just before and after the adoption of the catch-up provision.