According to a study by Benassy and Brezis (2012) on brain drain started back focusing mainly on welfare analyses in basic trade-theoretic frameworks. Such contributions asserted that brain drain had neutral effects on the source countries and also focused on the advantages of free migration for the global economy. This was justified by the fact that talented emigrants usually leave back few of their assets in their nation of origin complementing the remaining low and high skilled labor. These studies emphasized mainly on the contribution made by these highly-skilled migrants to knowledge and disregard the obsolete claims made about the losses suffered by developing nations (Benassy and Brezis, 2013).
Another wave of interest developed in 1990s. It is true that brain drain is associated with both beneficial and detrimental effects on the origin countries. Thus, the main objective was to illustrate the conditions because of which the total effect on welfare and development is negative or positive. This theoretical literature showed that the brain drain theory in particular circumstances prove to be beneficial for the source country. Newly available migration data and the effects of the feedbacks acquired from previous literature have resulted in significant and empirical literature. This has contributed to the evolution of a balanced viewpoint towards brain drain. Thus, recent literature is highly evidence-based which was impossible till date because of lacking comparative data regarding international migration (Byra, 2013).
Studies have shown that the key factors of the brain drain concept are the unpleasant nature of intellectual, economic and educational conditions in the developing nations. Lack of the resources required for research work; perception that the conditions would never improve; isolation from the global academic debates; lacking career progression; lack of freedom to conduct research; problems in becoming accredited as a qualified academic; lacking advanced career development and training opportunities and poor salary are some the factors which encourage researchers and academics to migrate (Byra, 2013). Nevertheless, it is also true that every skilled professional who migrates might not be looking for intellectual economic or educational opportunities. In some cases, they leave their home country because of political instability.
According to Bhargava and Docquier (2008) lack of skilled professionals in developed nations is a chief factor driving the extent and level of brain drain taking place in developing economies. Developed nations are undergoing a technological revolution which has triggered enormous growth in particular industries and increased demand for qualified professionals. As a result, developed nations are facing a lack of skilled individuals in rapidly growing industries. Thus, developed nations are dependent on developing nations to fulfill their labor requirements by offering multiple visa schemes (Bhargava and Docquier, 2008).
Demographic conditions in developed nations are another important factor. Some of these nations comprise of a progressively aging population which makes them face a dearth of labor in few sectors. This is the reason why few of these nations desire to recruit individuals from developing nations (Bhargava and Docquier, 2008). Existing statistics prove that every OECD nation other than the U.S. is suffering from deficit fertility rates. This means that this rate for women is much lower than a rate of 2.1 births per woman essential for maintaining the population level of developed nations which has resulted in an aging and shrinking population. Ageing is also aggravated by the increase in life expectancy that has been predicted to grow. Existing studies also show that the existing population age structure of the European nations such as Germany, Greece and Italy will be maintained through immigration only till 2050. For example, Germany expects to absorb 300,000 emigrants annually counting from 2010 for maintain its existing population age structure (Chang, 1992).
It is quite important to maintain the age structure of any nation’s population because it affects the ability of the nation to maintain its social welfare and pension arrangements. There are two other significant pull factors that need attention. Firstly, it is the existence of the migration networks within developed nations minimizing the adjustment issues in shifting to a new nation. Next is the existence of socially stable and safe environments in developed nations contributing to a stable and secure present as well as future (Daugeliene and Marcinkevičienė, 2009).