We identify the impact of intermediate goods markets imperfections on productivity downstream. Our empirical specification is based on a model of multifactor productivity (MFP) growth in which the effects of upstream competition can vary with distance to frontier. This model is estimated on a panel of fifteen OECD countries and twenty industries over 1985 to 2007. Competitive pressures are proxied with industry product market regulation data. We find evidence that anticompetitive upstream regulations have significantly curbed MFP growth over the past fifteen years, and more strongly so for observations that are close to the productivity frontier.