"Ideally, if you had the opportunity, would you like to move permanently to another country? Gallup Polls conducted worldwide between 2006 and 2008 reveal that more than one in every four people polled report a desire to move abroad. Specifically, across the 82 countries where Gallup asked this question, the median percentage saying they would like to move abroad was 26%. Although there are many reasons why people migrate, this percentage suggests that a substantial proportion of the earth's population may not be happy living where they now live..."
The full article can be found here and offers some useful insights into why people want to move to another country.