" Given that members of strong unions are highly paid, the obvious question is: are they highly paid because their unions are strong, or are their unions strong because they are highly paid? Defenders of the unions claim that the high pay of their members is a tribute to the strength of union organization, and that if only all workers were members of unions, all workers would be highly paid. The situation is, however, much more complex. Unions of highly skilled workers have unquestionably been able to raise the wages of their members; however, people who would in any event be highly paid are in a favorable position to form strong unions. Moreover, the ability of unions to raise the wages of some workers does not mean that universal unionism could raise the wages of all workers. On the contrary, and this is a fundamental source of misunderstanding, the gains that strong unions win for their members are primarily at the expense of other workers. "
― Milton Friedman , Free to Choose: A Personal Statement