18 December was the occasion to celebrate The International Migrants Day  [fr]. During the current global financial crisis, immigration from developing countries has been blamed by several political parties as the source of unemployment in their countries. Even though there hasn't been a single study, so far, that has proved that immigration has had in fact a meaningful role in the employment crisis, this belief remains strongly anchored in the minds of many.
Another phenomenon is also strongly anchored in the fabric of many developed societies: the increase in frequency of humanitarian campaigns around the holiday season.
Indeed, at every year's end in the more developed countries, one can observe campaigns that encourage their citizens to make donations to fight poverty in distant, less fortunate countries.
In addition to the recurring images of extreme poverty around the holidays (also referred to as “poverty porn ” in the development sector whenever pictures of poor people are excessively exploited by charities), there are some worrying statistics: 1.4 billion people live with less than $1.25 a day . Despite some undeniable economic progress in many African nations, social inequality is still even more striking on the African continent.
Economists also project that 1/3 of the poor in the world will reside on the African continent by 2015 . In fact, economic hardship is one of the key factors mentioned by the 700 million people worldwide who are eager to leave their countries of origin .
It often seems that the least developed countries just cannot escape the scourge of poverty, apparently powerless against the magnitude of the task at hand. Moreover, these countries are often reminded of their inability to meet the needs of the population without international support. Although international aid is a consequence of urgent crises, this situation is often felt as a recurring affront to national pride.
Various experts postulate, however, that extreme poverty isn't inevitable. The most radical solution to drastically reducing global poverty would be, for many economic experts, opening the borders between countries and allowing workers to migrate where labor is most needed. 
To this effect, Bagaric writes: :
Sending resources to impoverished places has merit. But it is a slow and fickle way of enhancing well-being. Instead, we directly pursue this aim by freeing up the flow of people so they can travel to where the goods are. [..] The starvation crisis is simply one of food distribution, not shortage. The best way to ameliorate Third World poverty is by massively increasing migration to the West. Left to their own devices many people would gravitate to life-sustaining resources, leading to a rough equilibrium between the world's resources and its population.
Lant Pritchett explains this notion in details in his book: Let Their People Come: Breaking the Policy Deadlock on International Labor Mobility. He quotes the results of a study claiming that :
Eliminating the planet’s remaining trade barriers would increase global GDP by around $US100 billion.
Eliminating immigration barriers, by comparison, would as much as double world income: that is, increase global GDP by $US60 trillion.
This added wealth would be shared, but the overwhelming beneficiaries would be people who now live in poor countries.
The World Bank published a study about immigrants’ contribution to the economy of their native countries through remittances from abroad. The study also shows that remittances are expected to reach as high as 351 billion dollars to the developing countries, and 481 billion dollars globally including the high-income countries. The study also mentions that :
Remittance flows to four of the six World Bank-designated developing regions grew faster than expected — by 11 percent to Eastern Europe and Central Asia, 10.1 percent to South Asia, 7.6 percent to East Asia and Pacific and 7.4 percent to Sub-Saharan Africa, despite the difficult economic conditions in Europe and other destinations of African migrants.
Needless to say, these non-orthodox theories are questioned by various experts and politicians. Frank Salter explains that the main concerns come from the inherent dysfunctions of every multicultural society :
Unrestricted migration would harm (Australia’s) national interests in ways documented by scholars in economics, sociology and related disciplines. Much of the harm is predictable from what is known about the dysfunctions of diversity. They include growing inequality in the especially invidious form of ethnic stratification [..] Diversity has also been associated with reduced democracy, slowed economic growth, falling social cohesion and foreign aid, as well as rising corruption and risk of civil conflict
From a political point of view, Europe is far from opening the borders, rather the contrary. In France, the Guéant Act restricts foreign graduates’ possibility of recruitment, giving birth to various reactions. Julie Owono, Global Voices member, describes the implications of this law and the reactions of various African bloggers  that see this law as an additional reason to contribute to the development of their countries. On the Rue89's blog, Owono adds that the Guéant Act also ostracizes financially limited foreign students  [fr].
In Africa, only a few experts have studied the concept of open borders, an idea that is, without doubt, too distant from the continent realities to persist. McGill University philosophy professor, Arash Abizadeh, doesn't encourage the opening of borders, yet states that the current border system can't be justified by a liberal egalitarian logic. Abidazeh states that  if we want to stick to the belief that “All men are born free and equal”, the constitution of borders is by itself a violation of such a principle.
Malagasy blogger Sly writes about the risks of opening the borders :
I'm African and while it seems that this would be a good idea there are some drawbacks
-spread of HIV and other diseases.
-refugees will form camps in more prosperous nations causing some problems.
Having said this some countries in Africa do have open borders with some neighbourig countries.
Sly refers to the fact that opening the borders between Kenya, Uganda and Ethiopia, in an attempt to increase regional economic integration, raised some major challenges in the region  during the recent food crisis.
This concept of using open borders to reduce global social inequalities implies that reducing global poverty would be the highest priority in the world. It would come before other important considerations such as national security and the national interests of each country. This theory of Pritchett and Magric certainly has a contentious side that aims to provoke a debate.
However, despite the claims of the international community that wants to reduce poverty worldwide, the open borders solution is only to be considered in specific contexts and won't take precedence over other items on the international agenda.