Within the immigration debate, libertarians have typically come down in favor of open borders by defending two main ideas: i) individuals have a right to free movement; and ii) immigration restrictions are economically inefficient, so that lifting them can make everyone better off. This entry describes the rationale for open borders from a libertarian perspective (in part by analogy to the debate around minimum wage laws). Three main objections within the immigration literature are then discussed: i) the view that states may restrict immigration to protect the interests (e.g. jobs) of their domestic needy; ii) the claim that restrictions are justified as a means of preserving culture; and iii) the influential argument that the right to free...