Overall, the study found, less than 10 percent of the U.S. population is participating in most online production activities, and having a college degree is a greater predictor of who will generate publicly available online content than being young and white.

The results suggest that the digital divide for social media users is wider between the haves and have-nots than it is between young and old, and underscore growing concerns that the poor and working classes lack the resources to participate fully in civic life, much of which is now online. That chasm is unlikely to break down until everyone has a host of digital production tools at both home and work, Schradie said.