There is not the space to consider all of these multiple perspectives, therefore, the focus of this chapter is on summarising the approaches and findings of what are arguably the three dominant and distinctive schools of thought on the topic. These are firstly, human capital theory and a more recent variation on this theory that argues major changes in the labour market of developed economies, notably the rising demand for higher skills and qualifications, is a response to ‘skill biased technical change’. Secondly, comparative international studies find that the acquisition of high-level intermediate skills by a large proportion of a workforce depends on a set of interlocking institutional arrangements governing not just training but also industrial relations, industry policy, education and welfare.