Process and Progress: Reviewing the Criminal Justice Act

Prado describes the results of a comprehensive study of the federal defender program and concludes that as the federal criminal justice system evolves, the Criminal Justice Act program must adapt to ever-changing conditions

Mozambique and natural disasters: human capital under threat

This paper assesses the effect of a sequence of natural disasters on children’s health that hit Mozambique at the start of the 21st Century. The disasters in question were the floods of 2000 and the droughts of the years 2002 and 2003. Height-for-age z-scores of children between 1 and 3 years old is used to capture the cumulative effects of this sequence of natural disasters. It was found that the effect of the disasters on these children’s height was, on average, -0.4236 standard deviations, which corresponds to the affected children being more than 1.5 cm shorter by the time of the survey. The findings in this paper are important because of the long term economic cost associated with the disasters, and urge the need for further public intervention to mitigate the damage caused by the shocks. This paper also contributes to the existing literature on the subject of the impact of shocks on child health in the developing world by focusing on measurement errors, differences in physical stature among ethnic groups and migratory movements.Mozambique; Health; Natural Disaster; Human Capital; Developing Country

A Generalized Sznajd Model

In the last decade the Sznajd Model has been successfully employed in modeling some properties and scale features of both proportional and majority elections. We propose a new version of the Sznajd model with a generalized bounded confidence rule - a rule that limits the convincing capability of agents and that is essential to allow coexistence of opinions in the stationary state. With an appropriate choice of parameters it can be reduced to previous models. We solved this new model both in a mean-field approach (for an arbitrary number of opinions) and numerically in a Barabasi-Albert network (for three and four opinions), studying the transient and the possible stationary states. We built the phase portrait for the special cases of three and four opinions, defining the attractors and their basins of attraction. Through this analysis, we were able to understand and explain discrepancies between mean-field and simulation results obtained in previous works for the usual Sznajd Model with bounded confidence and three opinions. Both the dynamical system approach and our generalized bounded confidence rule are quite general and we think it can be useful to the understanding of other similar models.Comment: 19 pages with 8 figures. Submitted to Physical Review

Connections between the Sznajd Model with General Confidence Rules and graph theory

The Sznajd model is a sociophysics model, that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favour bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modelled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We present some graph theory concepts, together with examples, and comparisons between the mean-field and simulations in Barab\'asi-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q>2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean-field, this would coincide with the q-voter model).Comment: 15 pages, 18 figures. To be submitted to Physical Revie