In 2008, Erica Chenoweth published a study comparing 323 violent and non-violent civil resistance campaigns between 1900 and 2006. Among her findings:
Non-violent campaigns worldwide were twice as likely to succeed as violent insurgencies.
This trend is increasing — in the last 50 years civil resistance has become increasingly frequent and effective, while violent insurgencies have become increasingly rare and unsuccessful.
Campaigns were successful once they'd achieved the active and sustained participation of just 3.5% of the population — and many succeeded with far less than that.
Every single campaign that surpassed the 3.5% threshold was a nonviolent one.
Campaigns that relied solely on non-violent methods were on average four times larger than the average violent campaign — and much more diverse and inclusive.
Erica presented her research at TEDxBoulder last month: