Washington Post (04.15.12) - Tuesday, April 17, 2012

According to researchers at New York University's Stern School of Business, the free classified-ad website Craigslist is linked to a 14 percent increase in the rate of new AIDS cases, or more than 6,500 new infections each year. They also say the site is related to a similar increase in syphilis infections.

"The ease of posting feeless ads requesting ... casual sex encourages the development of promiscuous behaviors within locations served by Craigslist," wrote Jason Chan and Anindya Ghose in "Internet's Dirty Secret: Assessing the Impact of Technology Shocks on the Outbreaks of Sexually Transmitted Diseases." [PNU editor's note: The study was presented in Washington at the 2011 Workshop on Health IT and Economics.] Chan and Ghose compared STD rates in 50 states and the District of Columbia before and after Craigslist began operating in each geographic area. The site brought more promiscuity and infection to most places, they said, noting it has "brought a culture of sexual openness to the younger generation not seen since the seventies." The study's data predate Craigslist's voluntary closure of its "adult services" section in 2010. However, the researchers said that the site's personal ads still get more traffic than other singles services such as Match.com and eHarmony.

"The case of Craigslist's entry leading to more STD infections serves to show that market participants exert little regulation over their casual sex behavior despite the known health risks involved," the authors wrote. However, they also said that if Craigslist closed down, sexual solicitation would move to another Internet site. Craigslist did not respond to requests for comment on the study.