In this chapter François Grin and François Vaillancourt assess the contribution of language economics to the question of what language (or languages) is (or are) used at work. After reviewing some essential cornerstones of language economics and its approach to language at work, they examine the determinants of language use in the workplace, and analyse the role of language in hiring procedures. They look in particular at the available evidence from Switzerland and Canada. Study of the economics of regional and minority languages presents a range of analytical difficulties, but they offer a framework that helps to ask the right questions and carry out the work to answer them in specific cases.