This doctoral thesis 1 investigates the research and development (R&D) practices in a transnational company (TNC), with the geography of the knowledge economy as an underlying theme. From this point of departure, the main research question that is discussed in the thesis is: How is research and development practice carried out in a transnational company under international expansion? In order to investigate this, the work builds on a qualitative case study of R&D practice in the Norwegian based TNC Hydro, a global supplier of aluminum. The empirical material is mainly derived from in depth interviews with researchers and research management within the company. Furthermore, the work in this thesis is a continuation of economic geography research related to an earlier interdisciplinary NTNU research project named Comparative Aluminum Research Program (CARP).In addition to a book chapter written in Norwegian and three articles written in English (part two), the thesis contains an introductory part (part one) that summarizes the work and puts it into an overall perspective. The analysis in this thesis builds on a number of theoretical debates and concepts, as the articles approaches the main research questions from different angles and is based on cases in the main case study. Most prominent is the theoretical discussions related to proximity, Communities of Practice, path dependence, networks and culture. Moreover, the thesis contributes to the recent debate on the evolutionary economic geography as a subdisciplinary perspective. The thesis illustrates how the transnational company facilitates a transnational R&D work environment by specific work practices and distinct organizational tools. This is the theme for the Norwegian book chapter Norwegian research and development serving foreign processing (Norsk forskning og utvikling i tjeneste for foredlingen i utlandet Stensheim og Karlsen 2008) 2 . The chapter is empirically based in a study of the internationally dispersed organization of Hydro’s extrusion division. Article number one, R&D practices and communities in the TNC – proximities and distances (Stensheim 2011)3, discusses the concept of proximity in relation to knowledge transfer. It illustrates how the transnational company compensates for the lack of geographical proximity by taking advantage of other forms of proximity based on relational aspects in the facilitation of R&D practices. However, the article supports earlier research in arguing for the importance of geographical proximity when it comes to knowledge transfer. By the analysis in this study, I also introduce a parallel notion to the proximity concept in relation to this, the notion of distances. This theoretical tool brings us closer to understand reasons behind challenges of transnational R&D practices. Related, the article states that the concept of Communities of Practice is an inappropriate tool of knowledge management in the transnational R&D work environment. The article states that the distances to a high degree are related to the TNCs geographical heterogeneity, however, it also inspired to investigate further how the endogenous organizational routines and practices influenced economic behaviour in the TNC. This theme, more specifically how R&D in the TNC is influenced by both a variety of 1 The geographical contexts and by different organizational contexts, is an underlying theme in the last two articles4. Article number two, Negotiating paths of TNC culture in the wake of a major cross-border acquisition, takes up to discussion the culture of the TNC. The institutional turn of economic geography has placed culture on the agenda as one of the aspects explaining geographical heterogeneity in economic activities. Despite this, culture is to a little degree unit of analysis in the published literature. The empirical point of departure of the article is a major cross-border acquisition made by Hydro in 2002. On this basis the article discusses how the TNC culture is influenced by a dynamic between influences from territorial institutions and organizations’ own routines and practices. Consequently, the article addresses a recent debate in economic geography discussing respectively the relational and the evolutionary as dominating current economic geography perspectives, implicitly considering the dichotomization between an evolutionary economic geography perspective and institutional approaches in economic geography in general. The mentioned acquisition also forms the basis for the empirical investigation in the third article, Geographies of TNC R&D networks. In this article, however, path dependence in networks is the main theme. This analysis shows that the acquisition is of little significance in the development of R&D networks, largely due to relational path dependence and the international nature of R&D in TNCs per se. Also this article demonstrates the connection between the relational economic geography and the evolutionary. Based on the conclusions drawn from the analysis of the articles, the thesis emphasizes drawing on an institutional approach that comprises both a relational and an evolutionary perspective on R&D practices in the TNC.