Defence date: 22 January 2016Examining Board: Prof. Evi Pappa, EUI, Supervisor; Prof. Almut Balleer, RWTH Aachen University; Prof. Peter Hansen, EUI; Prof. Giulio Zanella, University of Bologna.This thesis investigates labour market policies and the way they interact with labour market frictions. The first chapter of this thesis is dedicated to the introduction of a new method to measure skills mismatch in the labour market. By introducing a new index that uses employment distribution across sectors to measure labour demand and education distribution of unemployed workers, this new index reproduces some of the more relevant results in the literature. Given the nature of the index, the chapter can calculate it for as much as 74 countries per...