Particular branches of the economy provide a significant source of work for internal and international migrants seeking temporary or permanent employment opportunities. In turn, migrants are a vital source of skills and labour for several economic sectors. ILO constituents have voiced keen interest in learning more about migrant workers in particular economic sectors, for different reasons: on the one hand, there are concerns over the working conditions of migrant workers, and on the other hand, there is the desire of increased cross-border labour flows with a view to improving labour allocation and gaining efficiency. In an effort to close knowledge gaps regarding labour issues in economic sectors where migrant workers are found in considerable numbers, the ILO produced studies covering agriculture, construction, mining and the hotel industry.