The main question in this dissertation is: How can the emergence of local and commercial radio and the ensuing changes within each be understood in relation to intermedial and intramedial competition? This overarching question is broken down into four research questions. What driving forces contributed to the implementation of local and commercial radio respectively? (How can the competitive context of these two radio forms be described and periodized? In what ways have the practices of producing radio output, radio audiences and brands changed during the period covered by this study? What similarities and differences have emerged between local radio and commercial radio over time? This study can be seen as an institutional media history, focusing on two distinctive periods in the history of Swedish radio and television, Decentralization (1977-1987) and Commercialization (1987 onwards). The empirical material consists of documents, press clippings and some forty semi-structured in-depth interviews. Theoretically the dissertation combines political economy with a cultural perspective on media production and institutional intentionality. The empirical content is a two-part study on local radio and on commercial radio, presented through narrative principles of chronology and periodization. The results of the study are integrated to a large extent into the historical presentation that makes up the major part of the dissertation. More specifically, this historical exposition shows that issues of competition were important also before the deregulation of Swedish radio in 1993, and that the competitive conditions for these two parts of the Swedish radio landscape are on the one hand fundamentally different and on the other have become more similar over the years, especially when it comes to competitive strategies and production philosophies.