Hardin recognized two ways to avoid overexploiting commons. One is to privatize them, so that the owner has both costs and benefits. Now he has every incentive not to overgraze. The other is to regulate them by having an outside agency with the force of law behind it -- a government, in short -- restrict the number of cattle.
Claim:
The solution is neither privatization nor centralization. It is in the responses of local people getting together to solve their difficulties, as long as the community is small, stable, and communicating, and has a strong concern for the future. Such an autonomous community that interacts repeatedly can find a way to pursue the collective interest by altering the individual calculation of self-interest. This is something no distant government or indiviudal owner can do.