Landlocked countries which are surrounded by states with poor infrastructure are stuck in a poverty trap, according to Paul Collier, the renowned development economist.
The stats are hard to argue with. 38% of the worlds bottom billion live in landlocked countries. Looking at the map to the left, the vast majority of landlocked countries are classified as developing. 16 African states do not have coastal access.
This prevents development. Why? Trade. Simply trade.
To develop you need to trade internationally, importing and exporting. You need roads and rail to get to the coast and then you need sea ports to access overseas markets.
The transport infrastructure in Africa is notoriously weak. Crossing borders is time consuming and expensive. Those parts that are available are often unable (or unwilling) to deal with higher capacity.
The lack of alternate routes and ports means that trade is vulnerable to shocks. Uganda, Rwanda, Burundi, Dr Congo and south Sudan were massively impacted when Kenyan railroads were closed following the 2007/2008 election violence. No goods could be delivered to/from Mombasa port. Alternative ports were not feasible. Fuel prices tripled in Kampala. Essential commodities were unavailable.
Interesting, you might say, but there are plenty of landlocked countries in Europe (see the countries coloured orange on the map). Why do they not suffer the same fate? Well, European states have developed the infrastructure and agreements for easy cross border trade. The neighbours of landlocked European and Asian states also have well developed neighbouring state which serves as reliable markets for import/export.
When you combine landlocked (with underdeveloped neighbours) and some of the other factors (weak governance, conflict and the resource curse), you are stuck in colliers poverty trap.
All is not lost though. Great things are being done. Infrastructure is being improved and cross border cooperation is being strengthened (e.g. one stop border posts in East Africa). Coastal in-access and poor infrastructure has held it back but Africa is rising.