The free-rider problem is often cited as the rationale for union security agreements. A classic study of the free rider problem is presented in Mancur Olson's 1965 work, "The Logic of Collective Action." In labor relations, the free rider problem exists because the costs of organizing a union and negotiating a contract with the employer can be very high, and because employers will find it too costly to adopt multiple wage and benefit scales, some or all non-union members may find that the contract benefits them as well.