Africa and the Middle East
Source: "Last stop before desert"
Agadez is a city of 200,000 in Niger on the border of the Sahara desert. It exists because it is the last stop before the desert as you move north out of Africa. For centuries, it profited from trans-Saharan trade. Now it profits from trans-Saharan migration. After the toppling of Qadaffi in Libya in 2011, thousands of Africans moved through Agadez on their way to Tripoli, from which they hoped to cross the Mediterranean into Europe, usually through Italy.
From 2014 to the present (2018), about 600,000 migrants have passed through Agadez on their way to Tripoli. 2016 show the largest migration - 330,000 people that year. On average since 2000, 100,000 people a year pass through Agadez on their way to Libya. And the economy of Agadez is dependent upon these migrants: 6,000 residents were directly employed in trucking migrants across the desert and 1 in 2 households in Agadez indirectly profited from the flow.
Now the EU has put pressure on the government of Niger to enforce its anti-trafficking laws. Those caught transporting migrants today face jail time and confiscation of their vehicles. As a result, the flow of migrants has been reduced. Now less than 15,000 people a year pass through Agadez en route to Libya. Algeria has also stepped up its enforcement efforts and routinely turns back migrants who attempt to cross the border from Niger.
This means the United Nations has more refugees to deal with in the region. Those refugees include Sudanese fleeing violence in Darfur; 60,000 from Mali also fleeing war and 250,000 Nigerians fleeing persecution from the jihadist group Boko Haram.
Situation demonstrates how migration routes are tied to incentives. Like water, people flow through the paths of least resistance.
In the southernmost Libyan city of Sabha, migrants are reportedly being enslaved and sold.