Human migration happens for three main reasons that include economic, political, and environmental. The main advantages are to be able to send back remittances to alleviate the poverty in their home countries or families, higher wages, higher security, and greater opportunity to have a better life. Disadvantages include loss of host country’s culture for accommodating overwhelming number of immigrants and the possibility of brain drain that result from highly skilled people leaving their countries. Wilbur Zelinsky found the pattern of migration transition corresponds with the change in demographic transition. Social and economic change will cause the change in demographic transition and thus will shift the migration patterns. During stage 2 when population booms and the death rate falls rapidly, people tend to leave the country for greater opportunities. This leads to promote more international migration. However when the demographic transition goes into stage 3 and 4, the country’s internal migration increase and international migration falls because with a good health care, reliable food supply, water supply, and sanitation more people want to stay inside the country. Interregional migration in larger states like US, Russia, Canada, China, and Brazil are very common. The patterns of the migration for all the country’s above is from East to West except for China that moves from West to East. The migration occurs all for economic development but in a slightly different way. Therefore, it is very true and accurate to say the financial factors are the primary causes of human migration. Russia, for instance, used forced migration and economic incentives to move people to help build factories near raw materials than transport them. The government made decisions to locate new factories to spread out the population. Canada provided free land for people to promote the population to spread equally. China, like Russia, managed the population spread more through regulations. People must get permitted by the government to migrate. In Brazil, the government moved the capital from Rio to Brasilia to try to encourage migration to center of the country. US provide equal employment opportunities for all and Americans recognize the motives of immigrants as employment, family reunification, and better life. For example, Title VII of the Civil Rights Act of 1964 and Immigration and Nationality Act prohibits employers to discriminate because of national origin, race, or color. Even for illegal immigrants, there are still job opportunities for them because they have cheaper wages. They have smaller risk of getting deported because of the high acceptance of illegal immigrants in US (for several states). The greatest obstacle is the law established by government that restricts human migration because it will influence the will for people to migrate and their chance to migrate freely.