Yeah, and it gets really interesting when you look at examples from evolutionary biology, too. There's a pretty common population dynamic that goes on between "punish non-cooperation with some version of tit-for-tat" and "always cooperate because others will punish defectors" and "exploit others because there's enough non-cooperators for this to work as a strategy".

In normal times, companies don't pay more to non-union workers - but the company pays the same, and non-union workers get the benefits that union workers fought for, and the non-union folks don't have to pay union dues and the like. There's a very real reason why unions work to make themselves non-optional, and why businesses favor laws that enshrine a right to not pay union dues.