Historical research on cartel and competition policy has experienced a revival. One reason is the availability of a unique source material, namely the cartel registers that many countries maintained in the post-war period with the aim of controlling cartels and preventing "abuse". The Swedish register is being used in a research project at the Gothenburg School of Economics. The main purpose is to study issues related to (i) the control and monitoring of international cartel agreements and, to (ii) competition policy and free trade efforts in the post-war period. International agreements had to be registered if they had an effect on the domestic market and in the Swedish register there are about 350 agreements involving foreign firms. Many of the international cartel agreements were Nordic. Among other things, changes in the ownership structure of the Swedish business sector are studied, as well as the foreign companies' strategy towards Swedish cartels. Another problem area is the actions of the authorities as a result of free trade agreements. For example, what pressure did EFTA cooperation put on the Nordic cartel cooperation, and how did the authorities deal with the international cartels as the pressure to tackle the anti-competitive agreements increased? What was the impact of cooperation between the Nordic competition authorities (annual Nordic meetings)? And how did the cartels respond to the changes?