An important unanswered question about the role of unions in developed economies is whether the presence of unions affects long-run productivity. There is some evidence to suggest that the presence of a union
◦ reduces the demand for labour and therefore the demand for physical capital.
◦ reduces the expected profitability of installed capital and therefore leads to reduced capital investment by firms.
◦ reduces the level of employment (because of the union-wage premium) and thus raises the marginal product of labour.
◦ decreases the human capital of unionized workers, and therefore reduces long-run productivity.
◦ increases the human capital of unionized workers, which leads to increased long-run productivity for the firm.