This paper proposes a comprehensive overview of the ‘economics of language'. This field of research, which is grounded in the discipline of economics, displays a strong interdisciplinary orientation, which places it on the fringes of mainstream economics. It studies the ways in which linguistic and economic processes influence one another. It is also well placed to contribute to the evaluation of public policies regarding language, because it offers analytical tools for the systematic identification and measurement of the advantages and drawbacks of policy alternatives.I begin by discussing the reasons why an economic perspective on language is scientifically and politically relevant; I then review some of the attendant epistemological and methodological issues, before moving on to an overview of the main lines of research in language economics. A full section of this paper is devoted to the economic approach to language policy, and another focuses on an application to education policy, detailing the economics of second or foreign language education. The paper aims at making the key economic tools accessible to readers from varied academic backgrounds; it also emphasises the need to combine disciplines to develop an inclusive methodology for the selection, design, and implementation of language policies.