From the point of view of supporters, Moses(2006) supported that immigration could fill the gap job positions which can benefit the local citizen’s welfare and social security needs,also release the pressure of increasing number of ageing population. Borjas(1999) strongly support that immigration would benefit native works due to the increasing economic and redistributes income by immigration.
On the other hand, some people argue that immigration will lead to many adverse factors.On the environmental field, Erler, West and Marini (2007) propose the increasing population will cause more pollution and increasing pressure on limit resources. On the social side, Mellander(2001) pointed out that cheap labor immigrant would delay modernization. Last but not least, Greenwood(2007) indicated different cultures clash lead to financial problems due to the high cost of bi-lingual education and other factors.