I am very glad if I can offer a help. Here is another paper writen by Barzel, wishing you like this too.
Yoram Barzel, "The Entrepreneur's Reward for Self-Policing," Economic Inquiry 25: 103-116 (1987).
[URL=http://www.lib.uconn.edu/Economics/Entrepreneur's%20Reward.pdf]http://www.lib.uconn.edu/Economics/Entrepreneur's%20Reward.pdf[/URL]