Some proponents of immigration argue that the freedom of movement both within and between countries is a basic human right, and that the restrictive immigration policies, typical of nation-states, violate this human right of freedom of movement. Such arguments are common among ideologies like anarchism and libertarianism. As philosopher and Open borders activist Jacob Appel has written, "Treating human beings differently, simply because they were born on the opposite side of a national boundary, is hard to justify under any mainstream philosophical, religious or ethical theory."
Where immigration is permitted, it is typically selective. As of 2003, family reunification accounted for approximately two-thirds of legal immigration to the US every year. Ethnic selection, such as the White Australia policy, has generally disappeared, but priority is usually given to the educated, skilled, and wealthy. Less privileged individuals, including the mass of poor people in low-income countries, cannot avail themselves of the legal and protected immigration opportunities offered by wealthy states. This inequality has also been criticized as conflicting with the principle of equal opportunities. The fact that the door is closed for the unskilled, while at the same time many developed countries have a huge demand for unskilled labor, is a major factor in illegal immigration. The contradictory nature of this policy—which specifically disadvantages the unskilled immigrants while exploiting their labor—has also been criticized on ethical grounds.
Immigration policies which selectively grant freedom of movement to targeted individuals are intended to produce a net economic gain for the host country. They can also mean net loss for a poor donor country through the loss of the educated minority—a "brain drain". This can exacerbate the global inequality in standards of living that provided the motivation for the individual to migrate in the first place. One example of competition for skilled labour is active recruitment of health workers from developing countries by developed countries. There may however also be a "brain gain" to emigration, as migration opportunities lead to greater investments in education in developing countries. Overall, research suggests that migration is beneficial both to the receiving and sending countries.