RESUMEN
Many scholars claim that western European competition policies are essentially "right-wing". Such claims are often made directly (e.g. when such policies are attributed to the German Ordo-liberals and their influence), but also indirectly (e.g. when social democratic parties are portrayed as having systematically anti-market preferences). This article uses data from the post-world War II electoral manifestos of the French Parti Socialiste and the British Labour Party to challenge these views. Both the direct and indirect claims mentioned above are based on the exclusion from their samples of social democratic statements in favour of pro-market policies; this leads to overstating the difference between "Left" and "Right", and to the inference that when social democrats embrace competition policy they must be in crisis. Once these flaws are corrected we gain a more profound understanding of both social democracy and competition policy. Finally, the variation in social democrats' posture on antitrust needs to be explained, and this article takes the first steps in that direction by examining the potential influence of political-economic institutions, international agreements, and electoral concerns. The results point to the need for additional quantitative work.