Once just a supplement to the pension system, defined-contribution plans such as 401(k)s are growing and changing fast as they evolve into a linchpin of Americans' retirement savings and offer increasingly innovative investment options, a new study indicates.

Boosted by a widespread shift to automatic enrollment and other factors, the defined-contribution market is estimated by McKinsey & Co. to double in size by 2015 to $7.5 trillion to $8.5 trillion in assets under management.

That will make it three times larger than the once-dominant market for defined-benefit pensions, the consulting firm found in the study released Thursday.

The changes and expanding market should be good news for beleaguered consumers, forced to increasingly fund their own retirements in an era of vanishing pensions and shrinking Social Security funds. McKinsey says the increased options bring not only a wider range of choices but more opportunities to obtain investment-related advice and invest in lower-fee funds.

"The confluence of changes we are seeing in the market is signaling huge progress toward increasing the retirement readiness of the broader U.S. population," said Onur Erzan, one of the report's authors. "Defined-contribution plans are playing a much more critical and increasingly bigger role in that."

The findings also defy the notion that the defined-contribution market will decline when baby boomers retire. The analysis, based on interviews with dozens of experts and McKinsey's modeling, concludes that

SEATTLE (AP) -- Starbucks Corp. said Tuesday it will close 600 company-operated stores in the next year, up dramatically from its previous plan for 100 closures, a sign the coffee shop operator continues to struggle with the faltering U.S. economy and its own rapid expansion.

Seventy percent of the stores slated for closure had opened after the start of 2006, the company said in a statement.

To put it another way, Starbucks is closing 19 percent of all U.S. company-operated stores that opened in the last two years, Chief Financial Officer Pete Bocian said during a conference call.

About 12,000 workers, or 7 percent of Starbucks' global work force, will be affected by the closings, which are expected to take place between late July and the middle of 2009, spokeswoman Valerie O'Neil said.

O'Neil said most employees will be moved to nearby stores, but she did not know exactly how many jobs will be lost. Starbucks estimated $8 million in severance costs.

In total, the company forecast up to $348 million in charges related to the closures, $200 million to be booked in the fiscal third quarter ended June 30. Starbucks reports third-quarter results at the end of July.

The 500 additional stores set to be closed had been on an internal watch list for some time. They were not profitable, not expected to be profitable in the foreseeable future, and the "vast majority" had been