An index of labour market flexibility is, in the usual sense, a measure of the speed with which labour markets adjust to shocks. In times of crisis, such as the sovereign debt crisis of 2010, labour market flexibility is frequently mentioned as a necessary requirement for exiting the crisis. For instance, in a paper on Greece’s adjustment program, produced by the European Commission’s Directorate-General for Economic and Financial Affairs (ECFIN), it is written that “Employment Protection Legislation has been hampering the functioning of the labour market. [...] Major labour market reforms are now advanced well ahead of the December 2010 deadline. [...] These initiatives will increase adjustment capacity of firms, ultimately boosting employment.” (ECFIN, 2010a, pp.41-42). Even before the current sovereign debt crisis, the European Commission had recommended on several occasions the reform of labour markets as a necessary condition for making the European Union the world’s most competitive economy, as stated in the Lisbon Strategy (see, for example, European Commission, 2003).