In the 9th century, the economic expansion of the United States attracted immigrants, and in fact, almost 20% of the population was born today, a value of 10%, this which constitutes a large part of the working population. The reasons for emigration and immigration are sometimes mandatory in an employment contract. The cost of emigration, which involves the price of the ticket, and the implicit cost, loss of working time and loss of community ties, also contribute to motivating emigrants to leave their countries. For some migrants, education is the pull factor. The migration of retirees from rich countries towards a new type of migration. Obstacles to immigration come only from legal origins; Natural and social barriers to immigration can also be powerful. When you learn about an immigrant's country, everything is familiar to them: their family, their friends, their support network and their culture. Immigration policies have become strongly associated with other issues, such as national security, terrorism and, in Western Europe, particularly Islam as a new religion. Because of all these associations, immigration has become an emotional issue in many countries....