evidence: Illegal immigration is the migration of people into a country in violation of that country's immigration laws, or the continuous residence in a country without the legal right to do so. Illegal immigration tends to be financially upward, from poorer to richer countries.[1] Illegal residence in another country creates the risk of detention, deportation, and other imposed sanctions.[2] [...] Effects of illegal immigration [edit]Economy and labor market [edit]Based on data from the Immigration Policy Center, there are currently about nine million illegal immigrants in the U.S. There are about half a million more illegal immigrants every year. In addition, The United States spends about $3.8 billion on border enforcement each year.[36] [...] United States [edit]Approximately 11 million illegal immigrants were estimated to be living in the United States in 2006.[155] The Pew Hispanic Center estimated that this peaked at 12 million in March 2007 and declined to 11 million again in March 2009.[156] The majority of the illegal immigrants are from Mexico.[157]