>In 24 U.S. states, employees who are working in a unionized shop may be required to contribute towards the cost of representation (such as at disciplinary hearings) if their fellow employees have negotiated a union security clause in their contract with management. Dues are generally 1-2% of pay. However, union members and other workers covered by collective agreements get, on average, a 5-10% wage markup over their nonunionized (or uncovered) counterparts.
>Some states, especially in the south-central and south-eastern regions of the U.S., have outlawed union security clauses; this can cause controversy, as it allows some net beneficiaries of the union contract to avoid paying their portion of the costs of contract negotiation.
>Regardless of state, the Supreme Court has held that the Act prevents a person's union dues from being used without consent to fund political causes that may be opposed to the individual's personal politics. Instead, in states where union security clauses are permitted, such dissenters may elect to pay only the proportion of dues which go directly toward representation of workers.
https://en.wikipedia.org/wiki/Collective_bargaining#United_S...