Why are professional footbal players paid more in the U.S.A. than professional soccer players but in Europe and South America pro soccer players earn more? Relate your answer to marginal revenue product and the demand for labor. The percentage of the labor force belonging to a union has steadily dropped over the last 4 decades. Why do you think unions have experienced the decline over this period? What is the future of the union movement? What can unions do to reverse the trend