Final answer:
A two-tier pay plan can undermine solidarity within a union's membership, thus it's true that unions aiming to promote solidarity should not negotiate for such a system. Unions negotiate for higher wages, but this can lead to companies investing more in machinery and hiring fewer workers.
Step-by-step explanation:
The student's question asks if it is true or false that a union encouraged to promote solidarity among its members should not negotiate for a two-tier pay plan. The answer to this question is true. A two-tier pay system means that newer employees are paid less than those who have been with a company for a longer time, even when doing the same job. This can create divisions among workers and undermine unity, which is the opposite of the union's goal of solidarity. Negotiating for such a pay plan could lead to dissatisfaction and weakened collective power within the union membership.
Considering the broader context of union wage negotiations, a union can negotiate for wages above the market equilibrium by using the threat of a strike, achieving higher pay for its member workers. However, this can also lead to a trade-off where companies might invest in machinery to become more productive, potentially reducing the number of workers needed.