Economic education is an essential prerequisite for coping with economic-characterised problems in various life spheres, especially with socio-economic problems in the societal sphere. Making informed and reasoned decisions on socio-economic problems requires domain-specific content knowledge and domain-specific argumentation skills. Economic education is anchored in many framework curricula at secondary school level in German-speaking countries. Yet, despite its curricular and practical relevance, empirical studies in the economic domain that address both students' content knowledge and argumentation skills are rare. This article outlines a research design for a proposed intervention study that aims to promote and examine content knowledge and argumentation skills in socio-economic contexts. The research design is built on three core elements: (1) a workshop on teachers' pedagogical content knowledge, (2) a problem-oriented teaching/learning setting with authentic socio-economic problems and (3) instruments and frameworks to assess students' competence. The research design serves as a starting point for an internationally comparable research programme, primarily applicable for grammar schools in German-speaking countries.