Contrary to popular belief, the mass exodus of baby boomers from their big suburban single-family homes hasn't happened.

A new report by Fannie Mae dispels the notion that even the oldest boomers, those born between 1946 and 1955 and who are retiring in large numbers, are moving to smaller digs. Older and younger boomers are not pulling up stakes despite the fact that the number of married couples in the group with children under 18 at home has plummeted. "Between 2006 and 2012, the proportion of leading-edge boomer households consisting of a married couple with at least one child under age 18 declined from 10 percent to just 3 percent. Younger boomers [born from 1956 through 1964] have also begun to experience this life cycle transition en masse, with the share of nuclear families among this group falling from 35 percent to 20 percent," the report notes.

Meanwhile, the proportion of all boomers living in a single detached home actually increased from 2006 to 2012. What gives?

The report offers a few potential explanations, including that boomers prefer to remain in their single-family homes despite changing circumstances. Fannie Mae points to a 2010 AARP study that found that nearly nine in 10 boomers want to remain at their current residences as long as possible.

But it could also be that economic and housing market conditions brought on by the 2008 financial crisis have forced or encouraged boomers to stay put. Between 2006 and 2012, the average value of an owner-occupied single-family home owned by a boomer declined an average of 13 percent, Fannie Mae says. Some boomers might be in a negative equity position, while others may want to wait until the market improves before making a move.

The report notes that the data examined is only through 2012 and the situation may have begun to change. So far though, no major signs of a boomer mass exodus from single-family housing are apparent.

To read the report, click here.