Group size and incentives to contribute: A natural experiment at Chinese Wikipedia
In the the economics literature, the relationships to group size and motivation in the constructions of public goods is a very general and very important issue. The idea is, how is the size of a group connected to an individual within it's desire to contribution. If you benefit more people, are you motivated?
Wikipedia has been blocked in a China a number of times. The authors argue that one of the blocks was particularly long and unexpected and that most users, at the time, had no reason to suspect it would unblocked any time soon. Of course, users inside China were blocked, while other Chinese speaking users outside were not. This constituted a natural experiment.
The authors worked closely with two sysops from Chinese Wikipedia (User:Shizhao and User:Mountain) and focused on an 8 month window evenly placed around the third block of Wikipedia from October 2005 by Chinese authorities which ended up lasting for more than a year. They identified blocked and non-blocked users through editing patterns and also through the use of either traditional or simplified Chinese script. Their fundamental finding was an 46% decrease in the contributions of non-blocked users.