This just reminded me of microcredit in developing countries. The loans are often given to a group of several people, rather than one individual, and the repayments have to be made in public in the village. The group self-selects individuals likely to repay (so they don't have to suffer for the non-repayment of others), and the public nature of the credit put their reputation on the line.

This suggests a method of implementing "do stuff to avoid social status loss" - when you wish to commit yourself to doing something, you should make a public announcement to a group whose image of you matters. That way if you back down, you lose credibility in your social group.