This chapter discusses the arguments regarding the role of education as an economic investment and describes how these have evolved over time. It analyses how the academic arguments have helped shaped international and national policy debates on education. The chapter examines critically both the main arguments of the orthodox economics of education account and some of the critiques. It describes an image of an advertisement for private tuition classes in Hong Kong and also discusses the investments that many individuals, families and communities make in education. The chapter also examines the key theory of human capital and the related tool of rate of return analysis, which came to prominence between 1960 and 1980. It considers how the argument plays out in certain sub-sectors of education, and was crucial in a shift in education and development policy prescriptions away from higher education and towards primary schooling.