[warrenwilkinson]

I notice this in politics. Some people vote for charitable political parties, while they themselves never give to charity.

[pavlov]

This actually makes sense in politics, because a successful party can exercise charity on your behalf using tax money.

It's the "Swedish model" -- there private charity is rare, but public welfare and development aid is generally accepted and supported by voters.

[Retric]

It works as a stable multi player multi round prisoner's dilemma.

Basic strategy "always defect until everyone agrees not to while voting that everyone not defect."