Short-term increasing returns to production factors are usually found in empirical studies. We argue they can be due to omitted variables, particularly the intensity of factor utilization. Thanks to original French firm-level data (1992–2008), we show how increasing returns to scale disappear when working time, capacity utilization rate, and, particularly, capital operating time are introduced in the production function.

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.