A registered sex offender living nearby can make a home harder to sell and lower its value, according to a study by three Virginia professors.

The study found that the presence of a nearby offender reduced a home's value by about 9 percent and such houses took up to 10 percent longer to sell than homes with no registered sex offenders living close by.

"We find that sexual offenders have robust and economically large effects on nearby real estate," Longwood University professors Raymond Brastow, Bennie Waller and Scott Wentland wrote in the paper, which looked at data from central Virginia.

Realtors say their clients do research whether sex offenders live in areas where they are considering buying homes, and that information can hurt a neighborhood's desirability. "There are purchasers for whom, absolutely, especially if they have minor children, it is important to them," said Claire Forcier-Rowe, managing broker of Coldwell Banker Elite in Fredericksburg.

Forcier-Rowe said real estate professionals will tell homebuyers where they can find information about sex offenders, but it's "up to the purchaser to do their due diligence" with the research. John Thompson of Chantilly-based Samson Realty said some of his clients look up information about sex offenders in neighborhoods they're interested in, but he has "never had anyone say they're not going to buy as a result."

Brastow, one of the paper's authors, told The Washington Examiner that it made sense that the presence of sex offenders would affect home purchases because any "stigma or risk" associated with a home will affect its value.

But the magnitude of the sex offenders' influence surprised him, Brastow said. The study found that sex offenders living up to a mile away could still influence property values.

"Central Virginia residents assign a large risk to living near a convicted sex offender," the professors wrote, and homeowners value avoiding that risk more than they value a pool, fireplace, walk-in closet or additional bathroom. It's a good idea for potential buyers to investigate all components of a neighborhood's safety," said Walter Molony, spokesman for the National Association of Realtors.

Learning whether registered sex offenders are in the area is "something people should do when they're thinking about buying a home," Molony said.