Confusion over July's sales figures

The different July home sales tallies reported today -- and every month -- by the Massachusetts Association of Realtors and The Warren Group reveal a vexing issue.

But it's all in the data.

As I often explain in articles, their databases are different, which accounts for different results. The realtor group relies on the number of closings reported only by agents who are members of three multiple listing services in Massachusetts, for Cape Cod, the Berkshires and the largest one, MLS Property Information Network. The Massachusetts Association said that's roughly 80 percent of all agents in the state.

Warren Group goes to the courts and looks up closing documents statewide, totals them up, and reports those.

Warren Group's data base is much bigger, as can be seen in its tally of July's single-family sales in Massachusetts: 5,229 single-family sales in July, compared with MAR's report of 4,363 sales.

No database is perfect. Warren includes sales by owners, which could be as much as 10 percent of the market -- the real estate agents, for obvious reasons, do not.

Also, Warren's data in recent months has been more bearish than MAR's.

One reason may be because Warren includes what are known as " non-arms length" sales. In English, that means dad sells his daughter his condominium, valued at $500,000, for just $200,000. That may tend to pull down the prices.