Ensuring a good match between skills acquired in education and on the job and those required in the labour market is essential to make the most of investments in human capital and promote strong and inclusive growth. Unfortunately, in the OECD on average, about one in four workers are over-qualified - i.e. they possess higher qualifications than those required by their job - and just over one in five are under-qualified - i.e. they possess lower qualifications than those required by their job. In addition, some socio-demographic groups are more likely than others to be over-qualified - notably, immigrants and new labour market entrants who take some time to sort themselves into appropriate jobs - or under-qualified - notably, experienced workers lacking a formal qualification for the skills acquired on the labour market...