Racial Profiling and the War on Terror: Changing Trends and Perspectives

Minorities in the United States have often been treated unfairly by law enforcement agencies. Prior to the September 11, 2001, terrorist attack on the United States, Blacks were the main victims of racial profiling. Since the terrorist attack, however, Arabs and Muslims are becoming the primary targets for profiling by law enforcement agencies. There are some remarkable similarities between the profiling of Blacks and the profiling of Arabs and Muslims. In both cases, the fundamental problems with racial profiling are that it violates the civil liberties of innocent people and denies minorities the equal protection of the law. The War on Terror has redefined racial profiling. It has not only led to a shift in the target population, but it has also changed the ways in which racial profiling is conducted

The impact of leverage reduction on the equity risk level of the firm : an exploratory study of French firms

Although it is admitted that financing decisions affect the equity risk of the firm, few studies have been dedicated to the analysis of the relationship between risk and leverage. In fact, to our knowledge, no study has addressed the question of whether leverage reduction has an effect on equity risk. This exploratory paper addresses this issue using data on French firms. The results of the study show that leverage reduction significantly reduces equity risk. However, an indirect test of the relative importance of this effect indicates that the reduction may not lead to shifts in risk classes. In other words, asset risk is the more important risk factor.leverage reduction; equity risk; beta; risk class

A Simultaneous Determination of the Inter Vivos Transfer and the Unemployment Duration: the Malian case

This article aims to establish a link between the unemployment duration and the inter vivos transfers received by the unemployed individuals. We present a model where the transfer shapes the receiver's job search strategy while the donor bases it on the receiver's unemployment duration. Ultimately, a recursion arises and leads to a simulteanous determination of the transfer and the duration. The model aims to apprehend the job search behaviour in a context where the unemployment compensation system is weak or absent, like in some developing countries. We will take Mali as a study case.unemployment; inter-vivos transfer; job search; household economics.

Vanishingly Sparse Matrices and Expander Graphs, With Application to Compressed Sensing

We revisit the probabilistic construction of sparse random matrices where each column has a fixed number of nonzeros whose row indices are drawn uniformly at random with replacement. These matrices have a one-to-one correspondence with the adjacency matrices of fixed left degree expander graphs. We present formulae for the expected cardinality of the set of neighbors for these graphs, and present tail bounds on the probability that this cardinality will be less than the expected value. Deducible from these bounds are similar bounds for the expansion of the graph which is of interest in many applications. These bounds are derived through a more detailed analysis of collisions in unions of sets. Key to this analysis is a novel {\em dyadic splitting} technique. The analysis led to the derivation of better order constants that allow for quantitative theorems on existence of lossless expander graphs and hence the sparse random matrices we consider and also quantitative compressed sensing sampling theorems when using sparse non mean-zero measurement matrices.Comment: 17 pages, 12 Postscript figure

Bounds of restricted isometry constants in extreme asymptotics: formulae for Gaussian matrices

Restricted Isometry Constants (RICs) provide a measure of how far from an isometry a matrix can be when acting on sparse vectors. This, and related quantities, provide a mechanism by which standard eigen-analysis can be applied to topics relying on sparsity. RIC bounds have been presented for a variety of random matrices and matrix dimension and sparsity ranges. We provide explicitly formulae for RIC bounds, of n by N Gaussian matrices with sparsity k, in three settings: a) n/N fixed and k/n approaching zero, b) k/n fixed and n/N approaching zero, and c) n/N approaching zero with k/n decaying inverse logrithmically in N/n; in these three settings the RICs a) decay to zero, b) become unbounded (or approach inherent bounds), and c) approach a non-zero constant. Implications of these results for RIC based analysis of compressed sensing algorithms are presented.Comment: 40 pages, 5 figure

Structure of Anomalies of 4d SCFTs from M5-branes, and Anomaly Inflow

We study the 't Hooft anomalies of four-dimensional superconformal field theories that arise from M5-branes wrapped on a punctured Riemann surface. In general there are two independent contributions to the anomalies. There is a bulk term obtained by integrating the anomaly polynomial of the world-volume theory on the M5-branes over the Riemann surface; this contribution knows about the punctures only through its dependence on the Euler characteristic of the surface. The second set of contributions comes from local data at the punctures; these terms are independent from the bulk data of the surface. Using anomaly inflow in M-theory, we describe the general structure of the anomalies for cases when the four-dimensional theories preserve N=2 supersymmetry. We additionally discuss the anomalies corresponding to (p,q) punctures in N=1 theories.Comment: version 2, 38 pages. We simplified the discussion of the inflow procedure with punctures and removed the details of the explicit computation of the puncture anomalies in order to focus on arguing the main new ideas. Added clarification on main resul