Costly punishment does not always increase cooperation.
Wu JJ, Zhang BY, Zhou ZX, He QQ, Zheng XD, Cressman R, Tao Y.
Wu JJ, et al. Among authors: zhang by.
Proc Natl Acad Sci U S A. 2009 Oct 13;106(41):17448-51. doi: 10.1073/pnas.0905918106. Epub 2009 Sep 28.
Proc Natl Acad Sci U S A. 2009.
PMID: 19805085
Free PMC article.