Rent or buy? The math is changing

Only four years later, the couple see new signs of excess in the housing market and have decided to go back to renting. They are close to a deal to sell their house – for $1.35 million, a cool 67 percent gain.

“It just seems like the housing market came back so strongly, so fast, that maybe there’s a little bit of a bubble there,” said Mr. Gasparino, 37, an executive with the San Diego Padres.

Their decision reflects a new reality in many of the nation’s largest metropolitan areas. An analysis by The New York Times finds that in the country’s most expensive places, including New York, the San Francisco Bay Area and Los Angeles, buying a home again looks like a perilous investment, based on the relationship between their prices and rents or incomes. And in a longer list of areas, including Boston, Miami and Washington, prices have risen enough that buying is no longer the bargain it looked to be a few years ago.