It is more affordable to buy than to rent a two-bedroom home in 72 percent of the nation’s 50 largest cities, according to real estate website Trulia.com’s rent vs. buy index. Boston ranked 39th on the list, and was categorized as "less expensive to rent, but may make more financial sense to buy."

The index identified Miami; Las Vegas; Arlington, Texas; Mesa and Phoenix, Arizona; as the nation’s most affordable markets to buy compared to renting.

In contrast to this nationwide trend, renting is only less expensive than buying in four of the cities included in the study – namely New York, Seattle, Kansas City and San Francisco.

"Since the start of the ‘Great Recession,’ many former homeowners have flooded the rental market. Following the principles of supply and demand, renting has become relatively more expensive than buying in most markets," said Pete Flint, CEO and co-founder of Trulia. "Though necessary for achieving true economic recovery, stricter bank lending practices have also further aggravated the struggling housing market in the short term. Even highly-qualified homebuyers face intense scrutiny on their income, savings, existing debt and credit history before they can get a mortgage loan."

Cities overwhelmed by foreclosure filings and unemployment, including many cities in Florida, Arizona, Nevada and central California, typically correspond to more affordable markets for prospective buyers.

"Although owning a home is relatively more affordable in most cities, market conditions have caused an interesting demographic swap between traditional renters and buyers," said Tara-Nicholle Nelson, consumer educator for Trulia. "For example, lifelong renters are seizing the opportunity to become homeowners while affordability is high. At the same time, a growing number of long-time homeowners are finding themselves tenants – some by choice and others by necessity."