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In a clustered observational study, a treatment is assigned to groups and all units within the group are exposed to the treatment. We develop a new method for statistical adjustment in clustered observational studies using approximate balancing weights, a generalization of inverse propensity score weights that solve a convex optimization problem to find a set of weights that directly minimize a measure of covariate imbalance, subject to an additional penalty on the variance of the weights. We tailor the approximate balancing weights optimization problem to the clustered observational study setting by deriving an upper bound on the mean square error and finding weights that minimize this upper bound, linking the level of covariate balance to a bound on the bias. We implement the procedure by specializing the bound to a random cluster-level effects model, leading to a variance penalty that incorporates the signal-to-noise ratio and penalizes the weight on individuals and the total weight on groups differently according to the the intra-class correlation.
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Modelos Estatísticos , Estudos Observacionais como Assunto , Pontuação de Propensão , Humanos , Estudos Observacionais como Assunto/métodos , Análise por Conglomerados , Simulação por Computador , Viés , Projetos de Pesquisa , Razão Sinal-RuídoRESUMO
There is debate over whether Asian American students face additional barriers, relative to white students, when applying to selective colleges. Here we present the results from analyzing 685,709 applications submitted over five application cycles to 11 highly selective colleges (the "Ivy-11"). We estimate that Asian American applicants had 28% lower odds of ultimately attending an Ivy-11 school than white applicants with similar academic and extracurricular qualifications. The gap was particularly pronounced for students of South Asian descent (49% lower odds). Given the high yield rates and competitive financial aid policies of the schools we consider, the disparity in attendance rates is likely driven, at least in part, by admissions decisions. In particular, we offer evidence that this pattern stems from two factors. First, many selective colleges give preference to the children of alumni in admissions. We find that white applicants were substantially more likely to have such legacy status than Asian applicants. Second, we identify geographic disparities potentially reflective of admissions policies that disadvantage students from certain regions of the United States. We hope these results inform discussions on equity in higher education.
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Asiático , Critérios de Admissão Escolar , Humanos , Políticas , Estudantes , Estados Unidos , UniversidadesRESUMO
More than 40% of US high school students have access to Naviance, a proprietary tool designed to guide college search and application decisions. The tool displays, for individual colleges, the standardized test scores, grade-point averages, and admissions outcomes of past applicants from a student's high school, so long as a sufficient number of students from previous cohorts applied to a given college. This information is intended to help students focus their efforts on applying to the most suitable colleges, but it may also influence application decisions in undesirable ways. Using data on 70,000 college applicants across 220 public high schools, we assess the effects of access to Naviance on application undermatch, or applying only to schools for which a candidate is academically overqualified. By leveraging variation in the year that high schools adopted the tool, we estimate that Naviance increased application undermatching by more than 50% among 17,000 high-achieving students in our dataset. This phenomenon may be due to increased conservatism: Students may be less likely to apply to colleges when they know their academic qualifications fall below the average of admitted students from their high school. These results illustrate how information on college competitiveness, when not appropriately presented and contextualized, can lead to unintended consequences.
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Instituições Acadêmicas , Estudantes , Humanos , UniversidadesRESUMO
OBJECTIVES: Technology-based outreach offers promise for providing support to a broad population of postpartum mothers while keeping costs low. However, research on the efficacy of this approach is scarce. We conducted a pre-registered randomized pilot trial of the effects of a novel technology-based approach for supporting postpartum mothers - via text-based mentoring - from infant's birth through 18 months. METHODS: Mothers (n = 201) were recruited at West Penn Hospital in Pittsburgh, PA in the days immediately following delivery. Treatment mothers were matched with volunteer mentors who communicated with them entirely via text messages. Control mothers received monthly one-way texts on basic safety topics. Measures were collected via hospital records and mother surveys. We estimated treatment effects on mothers' parenting stress, mental health, knowledge of child development, engagement in language and literacy activities, and child milestones at 4- and 18-months postpartum. We used a systematic coding approach and simple descriptive statistics to analyze the treatment mother-mentor texting transcripts. RESULTS: We found no statistically significant impacts on targeted outcomes. However, impacts for some outcomes were meaningfully large (> 0.2 SDs). Analyses of texting transcripts showed that most mothers stayed engaged for the full 18-month study period and that mother-mentor pairs primarily discussed maternal wellbeing and child-focused topics. CONCLUSIONS FOR PRACTICE: Postpartum mothers will engage with mentors in a text-based mentoring program around important maternal and child health topics. More research and development on technology-based supports for parents in the early childhood years is needed.
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Depressão Pós-Parto , Tutoria , Envio de Mensagens de Texto , Feminino , Lactente , Humanos , Pré-Escolar , Mães , Mentores , Projetos Piloto , Período Pós-PartoRESUMO
This study investigated gaps in existing knowledge on justice, desire for revenge, and associated factors in disaster research through data collected nearly three years post disaster on justice and revenge from survivors of the September 11, 2001 (9/11) attacks. A volunteer sample of 379 employees of eight affected businesses completed interviews and self-report questionnaires. Individual ratings on satisfaction with justice and desire for revenge were compared with demographic characteristics, disaster-related experience, posttraumatic stress disorder (PTSD), disaster-related distress, anger, and concerns about danger and safety. High levels of desire for revenge and relatively low levels of satisfaction with accountability for perpetrators of the 9/11 attacks were endorsed. Most of the associations between the justice scores and the revenge score with the disaster response variables were directionally consistent. Dissatisfaction with perpetrator accountability was associated with greater desire for revenge. Both of these variables were associated with greater concerns about danger and endorsement of security regulations at the expense of personal freedoms.
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RATIONALE: Adult rats often produce 50-kHz ultrasonic vocalizations (USVs), particularly the frequency-modulated varieties, in appetitive situations. These calls are thought by some to reflect positive affective states and the reinforcing value of drugs such as amphetamine and cocaine. OBJECTIVE: The objective of this study was to determine whether the number of unconditioned 50-kHz USVs elicited by amphetamine predicts the development and/or magnitude of drug-conditioned motivation. METHODS: In three experiments, we recorded USVs before and after injections of 1 mg/kg amphetamine (i.v. or i.p.) administered once per session. Rats were categorized as "high callers" or "low callers" according to individual differences in the number of 50-kHz USVs elicited by their first amphetamine injection. We examined the conditioned appetitive behavior and conditioned place preference (CPP) that emerged in high and low callers after repeated pairings of amphetamine with specific contexts. We also examined whether amphetamine-induced calling was affected by treatment within an unfamiliar (test chamber) versus familiar (home cage) context. RESULTS: Within an unfamiliar environment, the high callers consistently produced more amphetamine-induced 50-kHz USVs than the low callers. Compared to the low callers, high callers showed significantly greater amphetamine CPP as well as enhanced conditioned 50-kHz USVs and locomotor activity during anticipation of amphetamine. Individual differences were stable when amphetamine was administered in test chambers, but when it was administered in home cages, low callers showed an increase in 50-kHz calling that matched the high callers. CONCLUSIONS: These findings suggest that individual differences in drug-induced USVs can reveal environment-sensitive traits involved in drug-related appetitive motivation.
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Anfetamina/farmacologia , Comportamento Animal/efeitos dos fármacos , Condicionamento Psicológico/efeitos dos fármacos , Vocalização Animal/efeitos dos fármacos , Anfetamina/administração & dosagem , Animais , Comportamento Apetitivo/efeitos dos fármacos , Masculino , Motivação , Ratos , Ratos Sprague-Dawley , Reforço Psicológico , Recompensa , UltrassomRESUMO
Despite decades of policy intervention to increase college entry among low-income students, substantial inequalities in college going by family income remain. Policy makers have largely overlooked the summer after high school as an important time period in students' transition to college. During the post-high school summer, however, students must complete a range of financial and informational tasks prior to college enrollment, yet no longer have access to high school counselors and have not engaged yet with their college community. Moreover, many come from families with little college-going experience. Recent research documents summer attrition rates ranging from 10 to 40 percent among students who had been accepted to college and declared an intention to enroll in college as of high school graduation. Encouragingly, several experimental interventions demonstrate that students' postsecondary plans are quite responsive to additional outreach during the summer months. Questions nonetheless remain about how to maximize the impact and cost effectiveness of summer support. This chapter reports on several randomized trials to investigate the impact of summer counselor outreach and support as well as the potential roles for technology and peer mentoring in mitigating summer attrition and helping students enroll and succeed in college. The authors conclude with implications for policy and practice.
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Pobreza/psicologia , Instituições Acadêmicas , Estudantes/psicologia , Universidades , Orientação Vocacional/métodos , Adolescente , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Orientação Vocacional/organização & administração , Orientação Vocacional/normasRESUMO
BACKGROUND: Results from MDRC's longitudinal, random-assignment evaluation of career-academy high schools reveal that several years after high-school completion, those randomized to receive the academy opportunity realized a $175 (11%) increase in monthly earnings, on average. OBJECTIVES: In this paper, I investigate the impact of duration of actual academy enrollment, as nearly half of treatment group students either never enrolled or participated for only a portion of high school. RESEARCH DESIGN: I capitalize on data from this experimental evaluation and utilize a principal stratification framework and Bayesian inference to investigate the causal impact of academy participation. SUBJECTS: This analysis focuses on a sample of 1,306 students across seven sites in the MDRC evaluation. MEASURES: Participation is measured by number of years of academy enrollment, and the outcome of interest is average monthly earnings in the period of four to eight years after high school graduation. RESULTS: I estimate an average causal effect of treatment assignment on subsequent monthly earnings of approximately $588 among males who remained enrolled in an academy throughout high school and more modest impacts among those who participated only partially. CONCLUSIONS: Different from an instrumental variables approach to treatment non-compliance, which allows for the estimation of linear returns to treatment take-up, the more general framework of principal stratification allows for the consideration of non-linear returns, although at the expense of additional model-based assumptions.