We use a non‐parametric approach to investigate the (inverse) relationship between farm productivity and farm size. A kernel regression is used on data of mixed cropping systems to study the determinants of production including different factors that have been identified in literature as missing variables in the testing of the inverse relationship such as soil quality, location and household heterogeneity. Household data on farm activities and crop production were gathered from 640 households in 2007 in two Northern provinces of Burundi. Our results do not reject the findings of an inverse relationship between farm size and productivity. However, we find that size returns vary substantially with farm size, that is, between 0.2 for the smallest farms and 0.8 for the largest farms. Other factors that significantly affect production include soil quality. Finally, we find a significant positive association between food security and farm size.

No abstract

In this paper, we study the relation between electoral competition and political selection, using a unique dataset containing detailed yearly information about members of the French National Assembly from 1958 to 2012. First, we innovate by using activity as a proxy for politicians' quality. As we gathered information on the many aspects of deputies' individual work, we use a nonparametric composite indicator of deputy activity that fully acknowledges the multidimensional nature of parliamentary work. Second, we do not impose any assumption about the relationship between electoral competition and political selection by using a fully nonparametric framework. Third, this method allows studying the evolution of the relationship between electoral competition and political selection over time. Overall, our results show that deputies elected in a priori contested districts have a higher overall activity, with the intensity of this relationship reaching its peak in the 80's but constantly decreasing since then.

We advocate a nonparametric multi-output framework to estimate outputspecific economies of scale and we apply this model to male prisons in England and Wales over the sample period 2009-2012. To estimate output-specific returns to scale in prisons, we consider not only the cost-per-place, but also qualitative outputs such as purposeful out-of-cell activity and successful reintegration. Furthermore, we introduce environmental heterogeneity using the characteristics of the prison(ers). England and Wales offers a unique example to study economies of scale in prisons as the UK has started to build new super-size prisons in order to replace the most outdated prisons.