When it comes to managing a defined contribution retirement account, just a modest increase in contributions will have a larger impact than fund performance.
   That was the finding of a recent study by Putnam Investments that took a look at what factors most influence the amount that can be saved in a defined contribution account over 15 years.
   The study looked at various scenarios for managing an account, including rotating funds every three years with top-quartile performers, using index funds for each asset class or even a "crystal ball" model that built an account with funds known ahead of time to be top performers.
The end result. according to the study, was that increases in contributions brought more of a return than the various test scenarios.
   The study found, for example, that the "crystal ball" account led to a 6% increase on returns after 15 years over an account made up of bottom-quartile performers.
   However, increasing the contribution rate from 2% to 4% of salary had 90 times the impact than changing from bottom-quartile to top-quartile funds.
   The study used the 15-year period covering January 1, 1990, to December 31, 2004.
   "The conclusion of this study is simple, but too often ignored," said David Tyrie, director of retirement services at Putnam Investments. "Saving more is the most powerful way to end up with more. Searching for the perfect mutual fund or allocation is a far less effective approach."