Free migration or open immigration is the position that people should be able to migrate to whatever country they choose, free of monetary charge. Although the two are not the same issue, free migration is similar in spirit to the concept of free trade, and both are advocated by free market economists on the grounds that economics is not a zero-sum game and that free markets are, in their opinion, the best way to create a fairer and balanced economic system, thereby increasing the overall economic benefits to all concerned parties. Notwithstanding noteworthy differences among these political ideologies, many libertarians, liberals, socialists, and anarchists advocate open immigration, as do Objectivists. From a human-rights perspective, free migration may be seen to complement Article 13 of the Universal Declaration on Human Rights:

1. Everyone has the right to freedom of movement and residence within the borders of each state.
2. Everyone has the right to leave any country, including his own, and to return to his country.

Arguments against free immigration are usually economical, cultural or security-related. Some arguments are nationalistic or what some critics claim to be "xenophobia", or ones similar to arguments against free trade; for example, protectionism. Specifically, an influx of cheap labor could easily deflate wages for workers who are already established in a particular labor market, and have a negative impact on the standard of living for the more established workers. Other critics of free immigration are concerned that it would be unfair to current homeowners if an influx of new residents greatly brought down the property values and attractiveness of living in that location, or alternatively, increased the demand to live in the city so much that the home owner would not be able to keep up with increased taxes from higher property values. However, free market economists believe that competition is the essence of a healthy economic system, and that any short-term negative impact on individual economic factors that is caused by free immigration is more than justified by the prospects of long-term growth for the economy as a whole. Other arguments include the general impact on the environment, infrastructure, population density, governmental costs, immigrant criminality, incompatible culture of immigrants and overall quality of life decrease.