In some industries, the labor productivity of union workers exceeds the labor productivity of nonunion workers. Which of the following explanations might help clarify the higher productivity of union workers?
A. All of these arguments provide reasons why productivity could be higher for union workers.
B. Higher union wage rates allow companies to attract more highly skilled workers.
C. Because union wages exceed nonunion wages, union workers are less likely to quit, which leads to a more experienced work force, and the higher union wages may also encourage workers to work harder.
D. Unions may provide information to companies about how to improve operations and eliminate problems in the work environment.