Mr Levy and Mr Temin argue that the failure of workers even with undergraduate degrees to keep up with productivity is due to a change in labour market institutions and norms that reduced the bargaining power of most US workers. 利维和特明指出,甚至受过大学教育的工人,收入也未能跟上生产率发展的步伐,这是因为劳动力市场的制度和规范发生了改变,使得多数美国工人的谈判力下降。