This led to an edited book published by Ashgate which brought together empirical and policy analyses, written by national experts, of three sending and four receiving countries. The publication generated a series of important results concerning, for instance, the role of labour demand versus push factors, and the quantitative and qualitative impacts of the uneven application of transitional restrictions on the free movement of labour by some EU15 countries. Other findings pointed to serious mismatch between immigrant workers’ skills and the jobs they actually perform in the receiving countries, suggesting that naïve views about labour flows and ‘factor equalisation’ are not appropriate to the real world. Developing this further, the key theme of the current publication is that of the skills and qualifications of migrant workers and how they interact with the duration of migration and the likelihood of return. These issues will be analysed against the backdrop of the very different economic and labour market situation since the onset of the economic crisis. This initially caused a severe drop in labour demand across the continent. Yet at the time of writing countries are emerging at very different speeds – with signs of prospective shortages of skilled labour, which is certain to affect migration flows.