It is often suggested in policy debates that the employment of highly educated workers in jobs traditionally held by lower skilled workers leads to skill wastage and a worsening labour market position for the less educated. This process is generally referred to as 'bumping down' or 'crowding out'. This argument challenges the policy of many developed countries to attach ever greater importance to knowledge as a means to increase international competitiveness. The authors in this book provide insights into the role of education in society by investigating the extent to which these arguments of overeducation and upgrading are valid. They bring together different approaches to obtain a complete picture of the debate in economics about under-utilization of skills and bumping down.