Migration has always been a central characteristic of the world most dynamic and productive economies. Throughout medieval Europe, states at the forefront of economic progress hosted entrepreneurs and laborers from across the continent. When the Netherlands led the world economy during the 1600s, 10 percent of its population was of foreign birth. Throughout the 18th, 19th and early 20th centuries mass migrations from Europe to the North America and Australasia enabled tens of millions of people to escape poverty and persecution and created what today rank as the world’s most prosperous societies. In recent years, migrant Diasporas, such as India’s techies –have made manifest contributions to the state of technology while also promoting global integration economic growth and poverty alleviation in their home countries.

With the dawn of European colonialism, migration took on a transcontinental dimension, with labor chasing wealth across the globe. Initially high costs and harsh conditions limited labor flows to intrepid aristocrats and those they exploited either by contract or coercion. Initially Britain was the main source of migrants-a consequence of its colonial reach, its economic preeminence, and its surging demographic profile. Yet, as industrial revolutions spread across Europe, uprooting rural population and fueling demographic booms the continent’s emigration flows diversified and grew significantly. By the dawn of the 20^th century close to 1.4 million migrants were crossing the Atlantic annually, the majority from the poorer region of southern and Eastern Europe. In total, between 1850 and 1914, some 55 million Europeans migrated, mostly to the United States. The majority of migrants incited a political backlash that eventually contributed to long- standing barriers to Asian immigration to the United States.

In 1917, The US introduced a literacy test for migrants intended to stifle further immigration of low- skilled workers. Later that year, the United States again entered world war1, disrupting Trans-Atlantic shipping routes and effectively bringing an end to the age of mass migration.

In France, Germany, the Netherlands, and the United Kingdom, rapid economic growth in the late 1940s and 1950s had generated a shortage of low wage labor. Initially, this demand was met by migrants from southern European countries though such source quickly proved insufficient. By the 1960s, countries across western Europe –Germany in particular were importing millions of ‘guest workers’ from Turkey and north Africa while the 1973 oil crisis and the ensuing high unemployment brought an abrupt end of guest workers programs in western Europe, the oil exporting countries in the middle east, later replicated and expanded upon the guest worker model.

Perhaps the most defining change in modern immigration however, came in the mid- 1960s when Australia, Canada and the US overhauled their immigration policies. These reforms not only allowed for a much greater volume of flows, but also opened the door to migration from non traditional sources in Africa, Asia and Latin America. Together with the sharp decline in cost and increased speed of intercontinental transport and communication, the reform of migration restrictions has ensured a steady growth in both the volume and diversity of migrant flows over recent decades.

Today, the US continues to accept more immigrants than any other country in the world. The Middle East has also emerged as a major host of migrants, particularly for low- skilled workers from south and Southeast Asia. Among countries of emigration, the middle income countries tend to have high rates of outflow. Mexico and the Philippines in particular are major exporters of labor. Philippines in particular has over seven million people overseas, equivalent to 10 percent of its population. Nevertheless the structure of immigration flows today broadly reflects those of the 19^th century which is a testament to the common human desires that underscore individual decision to migrant and common benefits that recipient society reap from the contribution of the migrants. Today, the immigration regimes of the richer countries aggressively guard the national interest and seek out the economic migrants who possess desirable socioeconomic characteristics. For example Canada and New Zealand- this is achieved through the point system which grants permanent residence to applicants who offer the right mix of skills, capital and adaptability.

High- income countries use skilled migrant programs to fill occupational shortages that cannot be met by training resident nationals. Historically, such flows have been concentrated in education and health-related services. During the 1990s, however, booms in telecommunication and in information and communication technology (ICT) led to a shortage of related skills in many high income countries, causing a renewed surge inflows of highly skilled migrants. There are around 3 million immigrants with university degrees residing in developed countries. With many of these degrees having been financed by source country governments, the total wealth transfer from poor to rich countries represented by the brain drain stands somewhere between US$ 45 and US$60 billion. Highly skilled workers in many countries generate the largest share of tax receipts. As a result, developing countries with respected system of higher education have emerged as major sources of particular skills for the developed world. India for instance has dominated the international market for computer- related skills accounting for over 60 percent of migrants heading to the United States to work in the field.

History shows that the world’s most productive economies often require and benefit from the presence of migrant workers. In Singapore, Southeast Asia’s richest state, migrants make up around one- quarter of the workforce. In Europe, those countries with the highest number of migrant workers- Switzerland and Luxembourg are also the wealthiest. The Arab Emirate of Dubai which is probably currently among the world’s fastest expanding areas of economic activity, has nine times as many migrant workers as it has native workers, By lowering the costs of production and bringing in needed skills and expertise, migrants can indeed offer large positive benefit to growing economies.

As Borjas (2004) claims, ‘illegal immigrants created a net burden for California’s tax payers of around US$2 to US$3 billion annually” [P.26]. His argument lacks sufficient evidence to justify his statement. However, there is a wide body of economic research that paints a very different picture of the fiscal impact of migration. Many Europeans studies for instance, concluded that immigrants- even those who are undocumented contribute more in taxes and pension contributions that they consume in benefits or other public services. In UK, the contribution of immigration to public finance is so large that , in the words of the United Nations, “ were it not for the immigrant population either public service would have to be cut or the government would need to increase the basic rate of income tax by one penny in the pound. In US, there is a big possibility that immigrant families are less likely to claim social welfare benefits than native families once income levels are controlled for.  

In addition, the content that migrants take the jobs of native workers is probably the most ubiquitous and controversial argument advanced against immigration. For economists, it has proved to be a difficult debate to settle empirically. Basic theory suggests that increasing the size of the labor force will lower the wage level all other things being equal. When a city or region receives an influx of immigrant labor, native workers may opt to move to other regions thereby masking and spreading out any changes to move into a region experiencing such an influx, causing local wages to go up. Migrants may also differ substantially from native workers in that they offer employers, and thus they may look for very different jobs.

Migrants who bring with them distinct skills or business contacts may also generate changes in technology, productivity and trade patterns that can affect an economy in ways quite unforeseen before their presence. It does not thus follow that simply because a particular region experiences an inflow of migrant labor, the average wage of native workers will decline relative to what it would have been otherwise.

In conclusion, inflows of skilled migrants can stimulate high-tech goods and services in destination countries. The magnitude of these benefits is often sizable particularly in countries with long established programs for attracting talents. In the US, for instance, it has been estimated that a quarter of Silicon Valley firms are headed by immigrants from China and India. Further, entrepreneurial immigrants have frequently played a crucial role in establishing trade and investment links between destination and source countries. These links often prove equally crucial in raising the living standard of native citizens. Immigrants can also help economies in much less tangible ways as well, such as by aiding in the adoption of foreign innovations and ideas.