This supplement to Applied Economics Quarterly reports on the 70th Annual Meeting of the Association of German Economic Research Institutes (ARGE-Institute), which took place in Berlin on April 19, 2007. The topic was "Energy Markets - Investment, Competition, and Regulation."Energy markets pose a major challenge for the economy, politics, and society: the entire structure of power generation is on the verge of a fundamental renewal. By dealing with the important current question of how regulation will affect investments in generation and transmission capacities within liberalized electricity and gas markets, the conference offered useful contributions for policy advice to the federal government. Keynote speaker Carl Christian von Weizsäcker discussed investments in energy markets, while Jean Michel Glachant, the second keynote speaker, considered the choice between a "Vibrant European Market and Industry or a Bunch of National Energy Champions." The other lectures focused on alternative strategies for renewable energies, biofuels as a climate policy strategy, as well as innovation, competition, and asymmetric strategic investment.From the editorial by Wolfgang Franz / Rainer Winkelmann / Klaus F. Zimmermann