Perhaps the most familiar such method is unionization or collective bargaining. Worker unions amplify the power of individual workers in relation to their employers by compelling employers to negotiate contracts with workers as a body. Unions may organize workers within a particular profession, within many professions, or within a single workplace or firm. Societies vary considerably in the degrees to which their workers are unionized and their labor laws friendly to union formation and power. Unions are presumptively justified on the grounds that workers who consensually form or join unions are exercising their right to freely associate with others with whom they share interests in order to promote those interests (Lindblom 2019), though if union membership is required in order to be employed in a particular workplace or industry, unionization may violate individuals right not to associate with others or to associate with (in this instance, to enter into an employment relationship) any party of their choosing (White 1998).Appealing to “republican liberty,” Mark Reiff (2020) has argued that unions should be viewed as a basic institution of society that protects workers’ liberty from exploitation by employers. On Reiff’s view, unionization should therefore be universal and compulsory.