• by Sarah Mahoney  @mahoney_sarah, May 14, 2013

As the economy continues to recover, affluent Millennials aren’t just ziplining in Costa Rica or buying one more mountain bike. A new study from Merrill Edge reports that Gen Y is saving for retirement even more aggressively than Baby Boomers.

In its study of “mass affluents,” the 25 million U.S. households with investable assets of between $50,000 and $250,000, it reports that those between the ages of 18 and 34 have already saved an average of $55,000 for retirement. And young investors are starting much earlier, with an average beginning age of 22 for retirement savings. By comparison, Baby Boomers began saving, on average, at 35.

And they’re making these investments now: Some 77% of Gen Y say they are planning to increase their nest egg over the next 12 months, and 57% intend to invest more in the stock market.

Some of the findings makes sense to expert Jeff Fromm, EVP at Barkley, and co-author of "Marketing to Millennials: Reach The Largest and Most Influential Generation of Consumers Ever."

"Given that many Millennials are delaying their decision to have children and the associated financial responsibility,” he says, "affluent Millennials have the opportunity to save more and have seen the market improve nicely. Millennials have a strong desire to travel and see the world, and saving enables them to pursue these aspirations.”

Well-heeled Gen Ys are optimistic about their future, and say they plan to save an average of $2.5 million by retirement, the Merrill study finds -- considerably more ambitious than compared to those working mass affluents ages 51-64, who anticipate saving just $260,000. (For the overall sample, the average retirement savings goal is $860,000.)

And those in the sample with young children are even more conservative, willing to cut back on family vacations (47%) or a new car (45%) in order to contribute to a college fund for their kids. And they are starting those savings plans earlier, with 95% of the sample with young kids having a savings plan in place, compared to 81% overall.

And the research indicates they are the least likely to count on Social Security to be part of their retirement income, with just 49% expecting to rely on it. (Of the 51-to-64 crowd, 68% are relying on Social Security.)

On that point, however, Fromm is skeptical.

“Millennials' desire for 'big' government is reflected in the most recent election results,” he says. “And this new data isn't consistent with other data I've reviewed.”