There has been huge recent coverage of the impending relaxation of migrant controls for workers from Romania and Bulgaria - two countries that joined the EU single market in 2007. Here are some different views on the issue.
The World Bank has recently put two short You Tube clips on their channel focusing on the importance of economies of scale, labour mobility and competitive cities as drivers of growth and development in Romania and Bulgaria. They are both worth a look as useful short revision clips for economists and geographers.
"Competitive cities are the main engine of economic development? Density, distance and division matter?"