Final answer:
Workers are given the option to not join a union by right-to-work laws, which were established under the Taft-Hartley Act of 1947.
Step-by-step explanation:
The laws that give workers the option of not joining the union, even at companies where the majority has voted to be represented by a union, are known as right-to-work laws. These laws were enacted under the Taft-Hartley Act of 1947, which gave states the authority to allow workers the freedom to choose whether to join or support a union. Right-to-work laws make union membership and payment of union dues voluntary, without job loss as a consequence. This backdrop highlights the international differences in union membership and the decline in union membership in the United States, suggesting that U.S. laws may be less supportive of union formation compared to other countries.