  The scope for free riding can be enormous. Suppose our large group would benefit from providing ourselves some good at cost to each of us. It is likely to be true that some subgroup, perhaps much smaller than the whole group, would already benefit if even only its own members contribute toward the larger group’s good. Suppose this is true for k ≪ n. This k-subgroup now faces its own collective action problem, one that is perhaps complicated by the sense that the large number of free riders are getting away with something unfairly. If one person in an exchange tried to free ride, the other person would most likely refuse to go along and the attempted free ride would fail. But if n − k members of our group attempt to free ride, the rest of us cannot punish the free riders by refusing to go along without harming our own interests.