Purpose: This article examines the prevalence of six economic terms in 17 Swedish upper-secondary school textbooks and how the language shifts between everyday and scientific language. Variations regarding content in the textbooks used in vocational programmes and preparatory programmes for higher education are also investigated. Design: Powerful knowledge (important knowledge within a subject) and semantic waves (variations between everyday and scientific language) are essential to cumulative knowledge building. These theories are used for quantitative and qualitative analyses of the textbooks. Findings: There are variations in the extent to which powerful economic terms appear and how the language shifts between everyday and scientific discourses in the textbooks analysed. Coverage and shifts are generally insufficient in textbooks used in vocational programmes. Practical implications: The importance of using powerful economic knowledge and shifting between everyday and scientific language in textbooks and teaching should be highlighted for policymakers, textbook authors and teacher educators.