19] In collective bargaining, an important element of power is the relative ability of each party to withstand a striI-te. 20} Both the public and private sectors use mediation to facilitate negotiations. 2i} The duty of fair representation mandated by the National Labor Relations Act {NLRE'L} requires that all bargaining, unit members, whether union members or not, have equal access to and representation by the union in the grievance procedure. 22] The union pay advantage causes employers to use less labor and more capital per 1worker than they 1.vottld otherwise, 1.vhicb reduces efficiency across society. 23} Because the United States does not have a strong history oi deep, classrbased divisions in society, the unionization rate and coverage are Iov.r when compared to those in Europe- 24} Worker representation on advisory boards is mandated by law in the United States, but not in Europe