The number of homes for sale in the Boston area has dropped from a year ago, increasing competition for properties and pushing up long-depressed prices, a trend real estate specialists say could speed the housing market’s recovery.
New figures released by the online brokerage firm Redfin.com show that the region’s inventory of single-family homes, condominiums, and townhouses dropped by more than 37 percent last month, to 16,947, compared with 27,024 for sale during July 2011. At the same time, Redfin reported the median price rose to $363,000 last month — 1.7 percent higher than in July 2011 — while sales increased by 9.3 percent.
Redfin’s numbers are based on broker listings and public records in Suffolk, Plymouth, Norfolk, Middlesex, and Essex counties.
But the for-sale shortage may soon come to an end, according to many housing economists and real estate specialists. They say higher values, escalating sales, and a realization that the market has stabilized are likely to persuade more property owners to sell their homes.
“Once people see houses are selling quickly, they will start listing their properties,’’ said Paul Willen, senior economist for the Federal Reserve Bank of Boston. “It is a self-correcting thing.”
Until now, many homeowners have been reluctant to sell for several reasons. Some are “underwater,” meaning they owe more on their mortgages than they could recoup in a sale. Others have stayed put because the nation’s high unemployment rate has limited their job options in other parts of the country. And in some cases, homeowners have simply been waiting for values to increase more before cashing out.
Laurie Cadigan, a real estate agent in Concord, said she is optimistic that many owners who took their homes off the market when sales and prices were falling sharply will soon decide it is time to try again.
“There is demand, and that has been lacking over the past couple of years,” Cadigan said.
The Massachusetts housing market has been slowly recovering from the housing malaise that started in the fall of 2005 and reached a bottom in 2009 after values fell about 20 percent. Single- family home values have been wavering since then, and home sales have increased over the past year, according to Warren Group, a Boston company that tracks local real estate.
In addition to the Redfin statistics, other housing indicators show local home values have been gaining. William Raveis Real Estate reported this week that the statewide median sale price for a single-family home reached $327,750 last month, 2.4 percent higher than during July 2011. That means half of the homes sold cost more, and half were below that price.
The S&P/Case-Shiller Home Price Indices, considered one of the best markers of home values because it measures repeat sales, showed Boston price increases in April and May.
Brokers are counting on finding more homeowners motivated by the encouraging data — people like Anne-Marie Baker-Medeiros and her husband, Frank Medeiros. The couple decided to press ahead with the sale of their modernized Colonial in Concord this summer, rather than waiting for the fall, when the market traditionally picks up momentum.
Three years ago, they considered selling, but real estate agents discouraged them, convinced the property would not attract a decent offer. Last month, however, they put the four-bedroom house on the market for $699,000, about $20,000 more than Medeiros paid for it in 2004.
“We are much more optimistic about the market,’’ Baker-Medeiros said.
Bill Raveis, chief executive of William Raveis Real Estate, a Connecticut company that does business throughout the Northeast, said he expects Massachusetts home values to increase by 5 to 10 percent this year as prospective buyers try to outbid each other. In July alone, he said, the number of homes for sale statewide — not just the Boston area — dropped by nearly 14 percent compared with the previous year.
“The inventory is going to be burned up, price increases are inevitable,’’ Raveis said. “That is good news for people who have mortgages that are higher than the value of their properties.”
The tight housing market is more extreme in downtown Boston and the immediate suburbs, said Daphna Fields, regional vice president of Coldwell Banker Residential Brokerage.
More properties are available outside the Route 128 loop, she said. “The further out you get . . . those numbers aren’t as acute,” said Fields. “But generally speaking, all over Massachusetts we have seen a major decline in inventory.’’
Some industry professionals are not sure low inventory will benefit the market.
Tim Ellis, Redfin’s real estate analyst, said a continued lack of available homes can slow sales.
“It is really just being a big damper on the whole market,” Ellis said. “Buyers are really frustrated right now. They look at all these homes but there is not much to choose from.”
Emil Frank and Zita Ephrem are among the prospective buyers waiting for more homes to tour. The couple have been looking for months to find a two-bedroom Back Bay or South End condominium in the $700,000 price range. Frank, 51, said he does not believe they are being too selective. There is not much to choose from, he said. “If the place is right, we’d pull the trigger,” Frank said.
In communities where sellers can expect to get their asking price — or more — real estate agents are aggressively seeking properties to list. Demand is far outstripping supply.
“For every listing that comes on, you could sell 10 more units just like it,” said John Ranco, a senior sales associate at Hammond Residential Real Estate in the South End.
Ranco said he makes a simple pitch to people hedging over whether it is time to list their home for sale. He tells them, “Who knows what is going to happen next year? You only know what you know today and today is what matters.”