Nonviolent resistance is not only the morally superior choice. It is also twice as effective as the violent variety.

That’s the startling and reassuring discovery by Maria Stephan and Erica Chenoweth, who analyzed an astonishing 323 resistance campaigns from 1900 to 2006.

“Our findings show that major nonviolent campaigns have achieved success 53 percent of the time, compared with 26 percent for violent resistance campaigns,” the authors note in the journal International Security. (The study is available as a PDF file at http://www.nonviolent-conflict.org)

The result is not that surprising, once you listen to the researchers’ reasoning.

“First, a campaign’s commitment to nonviolent methods enhances its domestic and international legitimacy and encourages more broad-based participation in the resistance, which translates into increased pressure being brought to bear on the target,” they state. “Second, whereas governments easily justify violent counterattacks against armed insurgents, regime violence against nonviolent movements is more likely to backfire against the regime.”

In an interesting aside that has relevance for our times, the authors also write that, “Our study does not explicitly compare terrorism to nonviolent resistance, but our argument sheds light on why terrorism has been so unsuccessful.”

To their credit, the authors don’t gloss over nonviolent campaigns that haven’t been successes. They give a clear-eyed assessment of the failure so far of the nonviolent movement in Burma, one of the three detailed case studies in the piece, along with East Timor and the Philippines.

In some sense, the authors have subjected to statistical analysis the notions of Gene Sharp, an influential Boston-based proponent of nonviolent change, someone they cite frequently in the footnotes. In his work, Sharp stresses the practical utility of nonviolence, de-emphasizing the moral aspects of it. He even asserts that for Gandhi, nonviolence was more of a pragmatic tool than a matter of principle, painting a picture that’s at variance with much of Gandhian scholarship. In an interview with me in 2006, Sharp declared that he derives his precepts from Gandhi himself.

Gandhi’s use of nonviolence “was pure pragmatism,” Sharp told me. “At the end of his life, he defends himself. He was accused of holding on to nonviolent means because of his religious belief. He says no. He says, I presented this as a political means of action, and that’s what I’m saying today. And it’s a misrepresentation to say that I presented this as a purely religious approach. He was very upset about that.”

One of the authors of the study, Maria Stephan, is at the International Center on Nonviolent Conflict. The group’s founders wrote a related book a few years ago, “A Force More Powerful: A Century of Nonviolent Conflict.” Erica Chenoweth is at the John F. Kennedy School of Government at Harvard.

This study is manna for those of us who believe in nonviolent resistance as a method of social change. We don’t have to justify it on moral grounds any more. The reason is even simpler now: Nonviolence is much more successful.