This cumulative doctoral thesis includes three articles that examine different aspects of the relationship between intellectual property (IP) protection and economic development. The first article reviews the impact of IP protection on foreign direct investment (FDI) by multinational enterprises (MNEs) in developing countries. Applying different panel data techniques to a newly created comprehensive FDI/IP dataset of 31 Swiss MNEs investing into 53 developing WTO Members over a period of 21 years (1990-2010), this study seeks to examine whether the local IP protection level has a significant positive effect on MNEs' decisions to invest in developing host countries and whether this effect differs between particular industry sectors, technological intensity levels and stages of host country development. The second article analyses the latest progress made in regulating digital trade on the bilateral and multilateral level. It looks into new specific IP rules for the digital environment and raises the question of what digital trade rules are needed today and in the future. The third article provides a comprehensive analysis of the transitional arrangements for least-developed countries (LDCs) in the TRIPS Agreement and in subsequent WTO decisions. Following the TRIPS Council Decision of June 2013 to extend the transition period for LDCs for another eight years, the authors propose potential avenues for WTO Members to meaningfully integrate the poorest countries into the international IP system. Abstracts in English and German have been provided for each of the three individual articles.