|AUTHOR||Richard Black et al.|
|ORGANIZATION||Development Research Centre on Migration|
According to estimates, the world's population will rise between 7.8 and 11.9 billion people by 2050, with a medium variant estimate of 9.2 billion. In turn, the number of people living outside their country of birth grew from 75 million in 1960 to 191 million in 2005, which is a rise from around 2.5 percent to 3 percent of the world's population. Assuming that the percentage of international migrants in the world either stays at 2005 levels or continues to rise at the same rate as in the last decades of the 20th century, with a median estimate of 275 million, 40 percent higher than at present. At the same time, it is clear that movement within national borders is at least as significant numerically as international migration, and is certainly the most significant form of migration for poor people.