ICT Skills and Employment: A Randomized Experiment

The aim of this paper is to evaluate the impact that the acquisition of Information and Communication Technologies (ICT) skills has on the labor market of two Latin-American cities: Buenos Aires and Bogota. Using cross-sectional data from an experiment that randomly assigned the ICT skills line in the resume, we assess the returns to ICT skills. For that, we submit approximately 11,000 fictitious Curricula Vitae (CVs) for real job vacancies published daily in the main job search engines in both cities. We estimate a binary choice model to identify differences in callbacks depending on ICT skills. We also analyze how gender, place of residence and occupational categories interact with ICT skills. Our econometric analysis supports previous literature suggesting that ICT skills could increase the probabilities of inclusion in the labor market, mainly for those at some level of disadvantage. To the best of our knowledge, this is the first study that quantifies the effect of ICT skills on employment. Our findings suggest that having ICT skills in the resume can increase the probability of receiving a callback by around 1 percent or more. This effect is much stronger in Bogota than in Buenos Aires, which suggests that ICT could be acting differently depending on the characteristics of the labor market.Information and Communication Technologies, hiring decisions, labor demand

Non-universal Voronoi cell shapes in amorphous ellipsoid packings

In particulate systems with short-range interactions, such as granular matter or simple fluids, local structure plays a pivotal role in determining the macroscopic physical properties. Here, we analyse local structure metrics derived from the Voronoi diagram of configurations of oblate ellipsoids, for various aspect ratios $\alpha$ and global volume fractions $\phi_g$. We focus on jammed static configurations of frictional ellipsoids, obtained by tomographic imaging and by discrete element method simulations. In particular, we consider the local packing fraction $\phi_l$, defined as the particle's volume divided by its Voronoi cell volume. We find that the probability $P(\phi_l)$ for a Voronoi cell to have a given local packing fraction shows the same scaling behaviour as function of $\phi_g$ as observed for random sphere packs. Surprisingly, this scaling behaviour is further found to be independent of the particle aspect ratio. By contrast, the typical Voronoi cell shape, quantified by the Minkowski tensor anisotropy index $\beta=\beta_0^{2,0}$, points towards a significant difference between random packings of spheres and those of oblate ellipsoids. While the average cell shape $\beta$ of all cells with a given value of $\phi_l$ is very similar in dense and loose jammed sphere packings, the structure of dense and loose ellipsoid packings differs substantially such that this does not hold true. This non-universality has implications for our understanding of jamming of aspherical particles.Comment: 6 pages, 5 figure