Aid and Growth: Have We Come Full Circle?

The micro-macro paradox has been revived. Despite broadly positive evaluations at the micro and meso-levels, recent literature has turned decidedly pessimistic with respect to the ability of foreign aid to foster economic growth. Policy implications, such as the complete cessation of aid to Africa, are being drawn on the basis of fragile evidence. This paper first assesses the aid-growth literature with a focus on recent contributions. The aid-growth literature is then framed, for the first time, in terms of the Rubin Causal Model, applied at the macroeconomic level. Our results show that aid has a positive and statistically significant causal effect on growth over the long run with point estimates at levels suggested by growth theory. We conclude that aid remains an important tool for enhancing the development prospects of poor nations.foreign aid; growth; aid effectiveness; causal effects

Aid and Growth: Have We Come Full Circle?

The micro-macro paradox has been revived. Despite broadly positive evaluations at the micro and meso-levels, recent literature has turned decidedly pessimistic with respect to the ability of foreign aid to foster economic growth. Policy implications, such as the complete cessation of aid to Africa, are being drawn on the basis of fragile evidence. This paper first assesses the aid-growth literature with a focus on recent contributions. The aid-growth literature is then framed, for the first time, in terms of the Rubin Causal Model, applied at the macroeconomic level. Our results show that aid has a positive and statistically significant causal effect on growth over the long run with point estimates at levels suggested by growth theory. We conclude that aid remains an important tool for enhancing the development prospects of poor nations.foreign aid, growth, aid effectiveness, causal effects

Deterministic and Probabilistic Binary Search in Graphs

We consider the following natural generalization of Binary Search: in a given undirected, positively weighted graph, one vertex is a target. The algorithm's task is to identify the target by adaptively querying vertices. In response to querying a node $q$, the algorithm learns either that $q$ is the target, or is given an edge out of $q$ that lies on a shortest path from $q$ to the target. We study this problem in a general noisy model in which each query independently receives a correct answer with probability $p > \frac{1}{2}$ (a known constant), and an (adversarial) incorrect one with probability $1-p$. Our main positive result is that when $p = 1$ (i.e., all answers are correct), $\log_2 n$ queries are always sufficient. For general $p$, we give an (almost information-theoretically optimal) algorithm that uses, in expectation, no more than $(1 - \delta)\frac{\log_2 n}{1 - H(p)} + o(\log n) + O(\log^2 (1/\delta))$ queries, and identifies the target correctly with probability at leas $1-\delta$. Here, $H(p) = -(p \log p + (1-p) \log(1-p))$ denotes the entropy. The first bound is achieved by the algorithm that iteratively queries a 1-median of the nodes not ruled out yet; the second bound by careful repeated invocations of a multiplicative weights algorithm. Even for $p = 1$, we show several hardness results for the problem of determining whether a target can be found using $K$ queries. Our upper bound of $\log_2 n$ implies a quasipolynomial-time algorithm for undirected connected graphs; we show that this is best-possible under the Strong Exponential Time Hypothesis (SETH). Furthermore, for directed graphs, or for undirected graphs with non-uniform node querying costs, the problem is PSPACE-complete. For a semi-adaptive version, in which one may query $r$ nodes each in $k$ rounds, we show membership in $\Sigma_{2k-1}$ in the polynomial hierarchy, and hardness for $\Sigma_{2k-5}$

Correlating Residual Stress with Personal and Professional Characteristics in Aircraft Pilots

Every day aircraft pilots must successfully resolve significant inflight situations and then manage the possibility of residual psychological and physiological stress. Previous research has shown primary attention is given to presignificant event training and stress management, however there remains an important gap in the current literature regarding postsignificant event stress within the aviation profession. The purpose of this cross-sectional quantitative study was to use the observational lens of stress theory and survey U.S. pilots who have experienced an inflight emergency, looking for correlation between factors such as age, gender, flight experience, and training against a pilot\u27s self-reported level of residual stress. Using snowball sampling methodology, 101 pilots were anonymously surveyed, with 89% responding that they had some level of residual stress via the Impact of Event Scale-Revised instrument. Using multiple linear regression analysis, the correlation between 9 personal and professional characteristics and pilot\u27s stress level was significant, at R2 =.22, adjusted R2=.14, F(9, 91) = 2.8, p \u3c .01. The sample\u27s correlation coefficient was .47, indicating that approximately 22% of the variance in the residual stress was accounted for by the 9 personal and professional characteristics. Findings from this research will help clarify how pilot training and demographics can affect postsignificant event stress. This knowledge will be an important contribution to the existing literature and enhance social initiatives though an increased awareness of residual stress within the pilot profession. The results can be used to increase aviation safety by enabling the industry and government entities to develop and implement effective stress training initiatives

Detection and fine-grained classification of cyberbullying events

In the current era of online interactions, both positive and negative experiences are abundant on the Web. As in real life, negative experiences can have a serious impact on youngsters. Recent studies have reported cybervictimization rates among teenagers that vary between 20% and 40%. In this paper, we focus on cyberbullying as a particular form of cybervictimization and explore its automatic detection and fine-grained classification. Data containing cyberbullying was collected from the social networking site Ask.fm. We developed and applied a new scheme for cyberbullying annotation, which describes the presence and severity of cyberbullying, a post author's role (harasser, victim or bystander) and a number of fine-grained categories related to cyberbullying, such as insults and threats. We present experimental results on the automatic detection of cyberbullying and explore the feasibility of detecting the more fine-grained cyberbullying categories in online posts. For the first task, an F-score of 55.39% is obtained. We observe that the detection of the fine-grained categories (e.g. threats) is more challenging, presumably due to data sparsity, and because they are often expressed in a subtle and implicit way

Technical approaches for measurement of human errors

Human error is a significant contributing factor in a very high proportion of civil transport, general aviation, and rotorcraft accidents. The technical details of a variety of proven approaches for the measurement of human errors in the context of the national airspace system are presented. Unobtrusive measurements suitable for cockpit operations and procedures in part of full mission simulation are emphasized. Procedure, system performance, and human operator centered measurements are discussed as they apply to the manual control, communication, supervisory, and monitoring tasks which are relevant to aviation operations

The Hurricane Exposure, Adversity, and Recovery Tool (HEART): Developing and Validating a Risk Screening Instrument for Youth Exposed to Hurricane Harvey

Given the increasing regularity with which severe (named) hurricanes arise, there is a need for valid, practically useful measures that facilitate child-centered post-hurricane situation analysis and needs assessment. Measures that accurately assess the most potent hurricane-related risk factors are essential to identifying youth at risk for developing posttraumatic stress reactions and providing them with effective post-disaster support. With feedback from community stakeholders (e.g., school personnel, physicians and hospital staff, community clinicians), we developed the Hurricane Exposure, Adversity, and Recovery Tool (HEART), a 29-item self-report measure of hurricane risk factors. Test development procedures included: (1) Reviewing the literature regarding hurricane exposure-related risk factors in youth; (2) Generating a developmentally-informed test item pool; (3) Conducting interviews with clinicians, as well as youth impacted by Hurricane Harvey, to evaluate the comprehensibility and acceptability of candidate items; and (4) evaluating endorsement rates for hurricane exposure-related risk factors among (N = 107) youth in an outpatient clinic specializing in the treatment of childhood trauma and loss. Disaster-related exposure, pre-existing indicators of risk, and ongoing post-disaster adversities were correlated with posttraumatic stress and depressive symptoms. These results provide support for an integrative approach to post-hurricane screening for both hurricane-specific (e.g., witnessing injuries) and non-specific (e.g., prior trauma) factors

Converging to efficiency : the Ramón y Cajal Program experience

We analyze the evolution on the design of a policy measure promoted by the Spanish Government: the Ramón y Cajal Program. In the first calls of the Program, an eligibility requirement for a researcher was a preacceptance from at least one Spanish research institution. This requirement was removed in the fourth call. We model the recruiting process as a twosided matching model to find the reason for the new design. We model the situation as if research centers decided by majority to play either the old or the new mechanism. Our results prove that in a repeated game and assuming that research personnel is scarce, even endogamic centers will prefer the new mechanism after a finite number of calls. We also analyze application data for the first five calls, finding empirical support to our assumptions and theoretical findings

An Exploration of Working Capacity and Return to Work after Cerebrovascular Accident

This portfolio contains three parts. Part one is a systematic literature review, in which the empirical literature concerning the psychological and neuropsychological comorbidities related to working capacity following stroke is reviewed. Part two is an empirical paper, which investigates the potential mediating effect of illness perceptions on the association between degree of comorbidities and post-stroke work status. Part three comprises the appendices