Getting the informatin revolution, one economist does.

Ed Glaeser for one., when dicussing the affect of Facebook on persons in proximity:

For example, surveys of Facebook users have found that the use of “Facebook to meet previously unknown people remained low and stable” and that “students view the primary audience for their profile to be people with whom they share an offline connection.”

Further research should reveal that Facebook allows friends to meet less often, but for longer periods. The affect should be GDP growth below potential.