Increasingly, our society relies on markets to coordinate economic exchange. Despite this our knowledge of how markets are formed and why they develop as they do is limited. This includes issues like how buyers and sellers are equipped to act and how products are qualified in order to be exchangeable on markets. Such equipping and qualifying is not uncomplicated which is illustrated e.g. by the unsought consequences often observed in connection to market de-regulation. This research project is based on a constructivist perspective where markets are viewed as results of three types of ongoing practices: exchange practice, representational practice and normalising practice. The objective is to increase our knowledge of how these practices shape markets and market actors. Two main questions are addressed. 1) How do theories contribute to shape markets? This issue will be studied by studying how theories and models are translated into rules and tools as part of market practice. 2) How are market actors shaped? Our starting point for studying this issue will be to regard market agency as a practical outcome rather than as a given characteristic. The project will run for 3 years and will address the issues through detailed empirical inquiries of mundane markets. It will be conducted in close cooperation with leading international scholars and is expected to enrich both scientific and public knowledge of markets.