Although markets can, under certain conditions, be effective mechanisms for resource allocation, their social importance is rather linked to their ability to generate change and development. When this happens, markets also change: new offerings are introduced, new insights about customers are formed, new customer relationships are built, new types of intermediaries are established, new methods of competition are tried. Nevertheless, our knowledge of change and development processes in markets is very shallow compared to the static analysis of the ideal market. This doctoral program is based on a dynamic and actor-based view of markets that focuses on how different actors try to change markets, and how they actually change through their efforts. It aims to identify, characterize and explain different types and patterns of market change. An increased understanding of change processes in markets is theoretically important, but also practically relevant for those who drive or are affected by changes in the organization and functioning of individual markets, e.g. companies, consumers, civil society organizations, and authorities. The program includes 4 PhD projects based on in-depth case studies of markets that are undergoing or have undergone significant transformations. These are: 1) the emergence of the sharing economy, 2) the emergence of legal cannabis markets in the US, 3) the merging of markets through the smart phone, and 4) the deregulation of passenger air travel.