Foreign born

The adjective foreign-born has two potential meanings:

• "born in a country other than that in which one resides."
• "foreign by birth."

The United Nations uses the first definition to estimate the international migrant stock, whenever this information is available. In countries lacking data on place of birth, the UN uses the country of citizenship instead.

On the other hand, the United States Census Bureau defines foreign-born as "anyone who is not a U.S. citizen at birth", which includes persons who have become U.S. citizens through naturalization but excludes persons born abroad to a U.S. citizen parent or parents.

According to the UN: "Equating international migrants with foreign citizens when estimating the migrant stock has important shortcomings. In countries where citizenship is conferred on the basis of jus sanguinis, people who were born in the country of residence may be included in the number of international migrants even though they may have never lived abroad. Conversely, persons who were born abroad and who naturalized in their country of residence are excluded from the stock of international migrants when using citizenship as the criterion to define international migrants."

The percentage of foreign born in a country is the product mostly of immigration rates, but is also affected by emigration rates and birth and death rates in the destination country. For example, the United Kingdom and Ireland are destination countries for migrants from Eastern Europe, Africa, and Asia, but are themselves source countries for immigration to other English-speaking countries.

The Holy See is unique in having 100% of its population foreign-born. The region with the highest rate of foreign-born residents is Oceania, with 21%, while Asia has less than 1%.

Countries with immigration rates above 25% tend to be wealthy countries with relatively open migration or labour laws, including Singapore, Australia, New Zealand, Switzerland and the Persian Gulf states.

The largest foreign-born population in the world is in the United States, which was home to 39 million foreign-born residents in 2012, or 12.6% of the population.

Direct figures on Pakistan's total foreign-born population are unavailable. However, estimates for specific immigrant communities can be found, which are as follows: 8.4% - 10% Indians (i.e., Muhajirs from India and their descendants), 1.6% - 2% Afghans, 1% Bengalis, 0.1 - 0.2% Burmese

1. Data for the cities listed below is from numerous sources.