Positive Average Effect Research Articles

Negative attitudes towards ethnic minorities and ethnic bullying and discrimination: a systematic review and meta-analysis

ABSTRACT According to the socio-ecological model, the social environment contributes to the acquisition and maintenance of negative attitudes towards ethnic minority groups. However, the strength of the association between negative attitudes at different levels (i.e. individual, peers) and ethnic bullying and discrimination has not yet been assessed. A systematic review and meta-analysis were conducted following the PRISMA guidelines. After duplicate screening, inclusion criteria and quality assessment, 10 studies (predominantly European, cross-sectional and involving secondary school students) were identified for descriptive analysis (i.e. systematic review) and 9 (22 assessments) were included in the meta-analysis. The results showed a positive average effect of attitudes towards ethnic minorities and ethnic bullying (d = .41, p < .001). Furthermore, the moderation analysis revealed a non-significant difference between the two levels of negative attitudes towards ethnic minorities (i.e. individual, peers) and ethnic bullying/discrimination (d = - .07, p = .09).

Does Aid Matter? A Systematic Review and Meta-Analysis of the Effects of Grant Aid on College Student Outcomes

The College Board reported that, in 2022–2023, about two thirds of $177 billion in U.S. financial assistance awarded to undergraduates through programs sponsored by the federal government, state governments, colleges and universities, philanthropic organizations, and other entities was in the form of grants. While researchers have examined the effects of individual grant aid programs on particular college student outcomes, results have indicated varied effects. Moreover, individual study findings have not been widely synthesized or examined to understand why some programs succeed where others do not. We conducted a comprehensive systematic review and meta-analysis to provide structure to this varied field and better understand programmatic effects. The results of the systematic searching and screening yielded 86 studies, across seven outcome domains, and the meta-analysis synthesized findings from 709 effect sizes from study samples representing 7,656,062 individuals. The meta-analytic results found small but meaningful positive average effects on college enrollment, credit accumulation, persistence, and completion. We cannot conclude from available studies that grant aid increased academic achievement or postcollege labor market outcomes. We also found that grants had larger positive effects on credit accumulation for studies with samples of students at 2-year institutions and studies that combined samples of 2- and 4-year students than for studies with samples of students at 4-year institutions only. Using a relatively new method called an evidence gap map, we illustrate where researchers should focus on producing new evidence.

Poised for growth: Exploring the relationship between accelerator program design and startup performance

AbstractResearch SummaryAccelerator programs provide valuable market feedback and education to participants that may improve startup performance. However, it is unclear whether the average effect of accelerator participation on startup performance post acceleration is positive, and if so, how this effect varies with accelerator program design. We analyze data from 8580 startups that made it past the initial selection stage at 408 accelerators in 176 countries between 2013 and 2019. We compare accelerated and non‐accelerated startups and find a positive average effect of accelerator participation on startup performance post acceleration. Moreover, we find that this effect varies substantially with program design, and depends on venture stage, industry, and founder expertise. Our findings highlight the impact of program design on the benefits that startups derive from accelerator participation.Managerial SummaryThe purpose of this study is to determine whether participation in startup accelerator programs generally leads to improved startup performance post acceleration and how the benefits of participation might vary with the design of these programs. We analyze data from 8580 startups that applied to and passed the initial selection phase at 408 accelerators in 176 countries over multiple cohorts between 2013 and 2019. Our results indicate that on average, startups that participate in accelerators perform better than those that are also selected but not accelerated. Furthermore, we find that the benefits that startups gain from being accelerated vary with the design of the program. Our findings highlight the importance of accelerator program design in influencing the extent of improvement in startup performance post acceleration.

The Effects of Online Social Identity Signals on Retailer Demand

Recent shifts in societal discourse have led digital platforms to support equity, inclusivity, and diversity by introducing identity-signaling features, for example, indicators of owner race or gender. In this work, we explore whether, when, and how using those features may impact retailer demand. We tackle this question via a multimethod study. We begin by conducting a controlled experiment on Prolific.co , presenting subjects with actual Google Places business profiles for a set of Black-owned restaurants in Chicago. We randomly vary the presence of Black- and women-owned labels in these profiles and assess subjects’ expectations of popularity and quality along various restaurant dimensions. Our results demonstrate that the Black-owned label, in particular, drives significant increases in all outcomes with the effects arising primarily from Black and democratically liberal subjects. Next, we conduct an archival analysis of the effect label adoption has on the physical foot traffic that retailers receive based on SafeGraph’s mobile patterns database. Our difference-in-differences estimations yield consistent results; we find evidence of a positive average effect on foot traffic volumes. Further, we show that a rise in visitors from liberal-leaning geographies drives these effects. We discuss implications for digital platform operators and retailers. This paper was accepted by Duncan Simester, marketing. Supplemental Material: The online appendix and data are available at https://doi.org/10.1287/mnsc.2023.01168 .

Acute hospital use in older adults following the 2015 Dutch reform of long-term care: an interrupted time series analysis

In 2015, the Dutch government implemented a long-term care (LTC) reform primarily designed to promote older adults to age-in-place. Increased proportions of older adults living in the community might have resulted in more and longer acute hospitalisations. The aims of this study were to evaluate whether the Dutch 2015 LTC reform was associated with immediate and longitudinal increases in the monthly rate of acute clinical hospitalisation and monthly average hospital length of stay (LOS) in adults aged 65 years or older. In this interrupted time series analysis of national hospital data (2009-18), we evaluated the association of the Dutch 2015 LTC reform with the monthly rate of acute clinical hospitalisation and monthly average LOS for older adults (aged ≥65 years). Patient-level episodic hospital data were provided by Dutch Hospital Data. Records were included that were defined as an acute clinical hospital admission for which a medical specialist decided treatment was necessary within 24 h. The analysis controlled for population growth (Dutch population data was provided by Statistics Netherlands) and seasonality, and calculated adjusted incident rate ratios (IRR). Before the 2015 LTC reform, the rate of acute monthly hospitalisation was increasing (IRR 1·002 [95% CI 1·001-1·002]). A positive average reform effect was observed (1·116 [1·070-1·165]), accompanied by a negative change in trend (0·997 [0·996-0·998]) that resulted in a decreasing trend over the post-reform period (0·998 [0·998-0·999]). The pre-reform trend of LOS was decreasing (0·998 [0·997-0·998]), and the 2015 reform exhibited a positive change in trend (1·002 [1·002-1·003]) that resulted in a stabilisation of LOS in the post-reform period (0·999 [0·999-1·000]). Our findings suggest that the increase in the rate of acute hospitalisation after the reform implementation was temporary, whereas the increase in LOS post-reform appeared to last longer than expected. These results have the potential to inform policy makers about effects of ageing-in-place LTC strategies on health and curative care. The Netherlands Organization for Health Research and Development, the Yale Claude Pepper Center, and the National Center for Advancing Translational Sciences, National Institutes of Health. For the Dutch translation of the abstract see Supplementary Materials section.

Focus on targeted interventions addressing bullying: what explains their success or failure?

ABSTRACT During four decades, numerous school-based bullying prevention programmes have been developed and evaluated. Meta-analyses indicate that such programmes have positive average effects, as compared with treatment as usual. However, the effects are small to moderate, and they are especially weak among some specific groups, such as adolescents. After all the progress made, too many young people still suffer from being bullied. Furthermore, findings suggest that the remaining victims may be even worse off than before in contexts where the overall level of victimization decreases – the phenomenon known as the Healthy Context Paradox . It is suggested that besides the average effects of preventive, universal multi-component programmes, more attention should be devoted to targeted interventions addressing specific cases of bullying. More precisely, we should investigate the characteristics and conditions of youth who remain victimized or continue bullying others despite targeted interventions, and identify factors – at multiple levels – that are related to intervention failure.

Understanding the effect of loneliness on unemployment: propensity score matching

BackgroundLoneliness and unemployment are each detrimental to health and well-being. Recent evidence suggests a potential bidirectional relationship between loneliness and unemployment in working age individuals. As most existing research focuses on the outcomes of unemployment, this paper seeks to understand the impact of loneliness on unemployment, potential interaction with physical health, and assess bidirectionality in the working age population.MethodsThis study utilised data from waves 9 (2017–19) and 10 (2018–2020) of the Understanding Society UK Household Longitudinal Study. Nearest-neighbour probit propensity score matching with at least one match was used to infer causality by mimicking randomisation. Analysis was conducted in three steps: propensity score estimation; matching; and stratification. Propensity scores were estimated controlling for age, gender, ethnicity, education, marital status, household composition, number of own children in household and region. Findings were confirmed in panel data random effect models, and heterogeneous treatment effects assessed by the matching-smoothing method.ResultsExperience of loneliness in at least one wave increased the probability of being unemployed in wave 10 by 17.5 [95%CI: 14.8, 20.2] percentage points. Subgroup analysis revealed a greater effect from sustained than transitory loneliness. Further exploratory analysis identified a positive average treatment effect, of smaller magnitude, for unemployment on loneliness suggesting bidirectionality in the relationship. The impact of loneliness on unemployment was further exacerbated by interaction with physical health.ConclusionsThis is the first study to directly consider the potentially bidirectional relationship between loneliness and unemployment through analysis of longitudinal data from a representative sample of the working age population. Findings reinforce the need for greater recognition of wider societal impacts of loneliness. Given the persisting and potentially scarring effects of both loneliness and unemployment on health and the economy, prevention of both experiences is key. Decreased loneliness could mitigate unemployment, and employment abate loneliness, which may in turn relate positively to other factors including health and quality of life. Thus, particular attention should be paid to loneliness with additional support from employers and government to improve health and well-being.

Meta-analysis of the relationship between Toxoplasma gondii and schizophrenia.

Toxoplasma gondii (T. gondii), which is an obligate intracellular protozoan parasite, could infect a wide range of hosts including humans. It infects approximately one-third of the entire human population. Infection with T. gondii can lead similar psychotic symptoms of schizophrenia. Starting from this information, numerous studies have revealed that maternal, acute and chronic T. gondii infections predispose to schizophrenia. The aim of this work was to evaluate the relationship between T. gondii and schizophrenia with a meta-analysis study using current data. 112 studies were reached using PubMed, Google Scholar and Council of Higher Education (YÖ̈K) Thesis Center databases. 15 studies which included a proportion of seropositive schizophrenia patients and controls were further examined in a meta-analysis. Among these studies, 13 of them showed a positive association between higher anti-T. gondii IgG level and patients with schizophrenia in the experimental groups whereas the remaining 2 studies showed a negative correlation. According to the random effects model, it was seen lower limit of 0.180 and upper limit of 0.490 with a standard error of 0.279 and a 95% confidence interval. The average effect size value was calculated as 0.335. This result having positive average effect size indicated that there was a positive association between T. gondii infection with a higher IgG level and the presence of schizophrenia.

How to dampen the surge of non-communicable diseases in Southeast Asia: insights from a systematic review and meta-analysis.

Non-communicable diseases (NCDs), such as diabetes, cancer, cardiovascular diseases and chronic respiratory diseases, have overtaken infectious diseases as the number one cause of death worldwide. The rise of these diseases is especially grave in Southeast Asia, where existing research however falls short on offering guidance on how policy can best prevent and control NCDs in the region. Additionally, low- and middle-income countries in Southeast Asia cannot directly incorporate lessons drawn from interventions in richer countries, since health system capacities and human and financial resources are thoroughly different. Preventive interventions, thus, need to correspond to local capacities and require contextual solutions. In this article, we provide a systematic review of a wide scope of NCD interventions conducted in Southeast Asia to inform about existing intervention designs and to derive sound evidence of their effectiveness. Our literature search results in 51 studies from five Southeast Asian countries from which we can extract 204 estimates. We sort the studies into six intervention categories and analyse them with respect to 23 different health and behavioural outcomes. While we find positive and significant average effects across all six types of interventions, we also document evidence of substantial publication bias. Using a meta-regression approach in which we correct for the publication bias, we instead fail to confirm positive average effects for some interventions. Especially dietary and physical activity interventions fail to achieve improvements in analysed health outcomes, while programs focusing on smoking cessation, on the take-up of preventive screening activities or educating patients on how to cope with NCDs achieve sizeable effects. We also present evidence that the size of the effect differs with the participants’ characteristics as well as with design features of the intervention. For local policymakers, the results provide important knowledge on how to address the increasing NCD burden in the coming years.

A meta-analysis of loneliness and use of primary health care

ABSTRACT Loneliness is a growing public health concern that is associated with a range of negative health outcomes. The extent to which loneliness may also be associated with greater use of primary health care remains unclear. The present meta-analysis aimed to address this gap by quantifying research on the association of loneliness to primary health care use. The database searches yielded 23 eligible studies with 25 effects, total N = 113,639. A random effects meta-analysis revealed a small positive average effect size (ravg = .094; 95% CI [.07, .12])between loneliness and the use of primary care that increased in magnitude as the proportion of females in the samples increased. Studies that used objective measures of primary care use yielded effects that were significantly larger than those using self-report measures. The effects were robust to differences in age and type of health-care systems, and the type of loneliness scale (single versus multi-item). The findings from this first comprehensive meta-analysis of the association of loneliness with use of primary care indicate that people who experience loneliness make a greater number of visits to primary-care practitioners. This evidence highlights the practical impact of loneliness on health-care use when viewed at the population level.

Measuring the evolution of competition and the impact of the financial reform in the Mexican banking sector, 2008–2019

This paper analyzes the monthly evolution of bank competition in Mexico from 2008 to 2019 using different measures. Subsequently, we analyze whether the 2014 financial reform had an effect on some of our competition measures. We use ordinary and quantile regression techniques and Markov switching models to identify changes in regimes. We find partial empirical evidence supporting the idea that the reform had a positive average effect and increased banks’ competition intensity during a few years. However, we also document heterogeneity as some large banks benefited from an increase in their market power. We perform several robustness tests and report that our measures lead to values that are congruent and similar to those available in the literature. The main policy lesson of our research is that regulators could benefit from the monitoring of competition evolution using a finer time frequency.

Are active labour market policies effective for the older unemployed? A meta-evaluation

AbstractWe present a meta-evaluation of the literature on the impacts of active labour market policies for unemployed people over 50, extracting 82 impacts for analysis. The meta-evaluation includes only impact evaluations that examine both a group of beneficiaries and a control group of comparable non-beneficiaries. On average, we find that active policies have a slightly negative effect (−0.8 percentage points) on the probability of unemployed people over 50 finding a job and that this negative effect disappears 24 months after policy implementation. However, this effect is very different when disaggregated by policy type. Direct job creation policies have a clear negative effect (−3.9 percentage points), and training policies have a positive average effect, either in isolation (2.4 percentage points) or when combined with search assistance or counselling (1.7 percentage points). We also find slight differences by gender, with the effect of active policies being greater for women than for men. These results have important implications, given that the European Commission and the Organisation for Economic Co-operation and Development have made active policies the cornerstone of their efforts to improve the re-employment of older people. Our results support training policies, either in isolation or in combination with search assistance and counselling. The greatest impacts are obtained after 12 months of policy implementation.

Evaluating the impact of preferential trade agreement on fishery imports: An application of difference‐in‐differences with matching method

AbstractThe purpose of thisstudy is to investigate the average treatment effect of the preferential tariff scheme at the HS 6‐digit level on the imports of fishery products between each OECD country and the world. The estimated results by employing a difference‐in‐differences with matching method show statistically positive average treatment effects for imports of frozen yellowfin tuna (HS030342) and fresh long‐finned tuna (HS030231) in many countries. However, there are also several negative average treatment effects on imports, implying that several OECD countries do not utilize preferential tariff schemes with exporter countries with sufficient productivity. This study fills the gap in the literature by providing more rigorous insights in the discussion regarding the trade creation/diversion effect of preferential trade agreements (PTAs).

Genetic diversity, population structure and validation of SSR markers linked to Sw-5 and I-2 genes in tomato germplasm.

The online version contains supplementary material available at 10.1007/s12298-021-01037-8.

The Effect of Using Technology in Education on Academic Achievement of Students: The Case of Geographical Information Systems

The objective of this study was to determine the effect of Geographic Information Systems, one of the educational technologies, on the academic performance of students. In accordance with this purpose, to combine the results of independent experimental studies, the meta-analysis method was put into use. Within this context, as a result of the literature review, in the meta-analysis, 17 experimental studies conducted between the years 2007 and 2020 were included. The total sample size of the mentioned studies was 620 in the experimental group and 607 in the control group. Thalheimer and Cook's (2002) classification was used in calculating the effect size values in the study in which the random effects model was used. Publication bias in research; Funnel Plot was tested with Rosenthal Fail Safe N value, cut and fill method of Duval and Tweedie and Begg-Mazumdar statistics, and studies included in meta-analysis were found to be heterogeneous. The effect of moderator variables, which are thought to influence academic achievement, was examined. Q and p significance tests were used to calculate the effect of moderator variables. According to the results of the study, it has been determined that GIS has a very wide (+1,193) effect on academic achievement. Positive average effect size indicates a change in favour of the experimental group. It was concluded that among the moderator variables, the study type, class level and sample size did not create a significant change in the effect size, and the year variable created a significant difference in the effect size.

Combining parenthood and work: transmission channels and heterogeneous returns to early public childcare

We exploit local and temporal variation in the availability of public childcare for children under the age of three that induces exogenous variation in childcare attendance. We find a weak, positive average treatment effect (ATE) on maternal labor supply. The estimation of the average treatment effect is interesting – however, possibly masking important effect heterogeneity. Examining selection behavior and estimating marginal treatment effects along the distribution of observables and unobservables that drive individual treatment decisions reveal transmission channels and uncover substantial heterogeneity in marginal returns from public childcare reforms. By estimating marginal returns, we detect reverse selection on gains at the intensive margin, whereas a substantial share (40 percent) of mothers with median desire to public childcare react with increased probability to work full time. Thus, if the supply of public childcare is expanded from a modest to a more generous level of coverage, those with average resistance towards early public childcare do gain. At the extensive margin, positive selection on gains is found; however, only a small fraction of mothers with the lowest distaste for early public childcare shift from non-employment to part-time jobs.

Crédito Rural e Agricultura Familiar no Brasil: uma avaliação do Programa Nacional de Fortalecimento da Agricultura Familiar

Este estudo tem como objetivo principal apresentar e discutir os impactos do Programa Nacional de Fortalecimento da Agricultura Familiar (Pronaf) sobre a renda e a produtividade na agricultura familiar brasileira. Para alcançar o objetivo proposto, foram utilizados dados da Pesquisa Nacional por Amostra de Domicílios (PNAD) do ano de 2014 e empregou-se como método de análise o Propensity Score Matching (PSM). Observou-se que o programa apresenta efeito médio positivo de 10,9% sobre a renda dos seus beneficiários em relação aos não beneficiários. Quanto ao efeito do Pronaf sobre a produtividade agropecuária, os beneficiários do Pronaf apresentam em média uma produtividade 15,2% maior em comparação aos não beneficiários.

Evaluation of conditional treatment effects of adjuvant treatments on patients with synovial sarcoma using Bayesian subgroup analysis

BackgroundThe impact of adjuvant chemotherapy or radiation therapy on the survival of patients with synovial sarcoma (SS), which is a rare soft-tissue sarcoma, remains controversial. Bayesian statistical approaches and propensity score matching can be employed to infer treatment effects using observational data. Thus, this study aimed to identify the individual treatment effects of adjuvant therapies on the overall survival of SS patients and recognize subgroups of patients who can benefit from specific treatments using Bayesian subgroup analyses.MethodsWe analyzed data from patients with SS obtained from the surveillance, epidemiology, and end results (SEER) public database. These data were collected between 1984 and 2014. The treatment effects of chemotherapy and radiation therapy on overall survival were evaluated using propensity score matching. Subgroups that could benefit from radiation therapy or chemotherapy were identified using Bayesian subgroup analyses.ResultsBased on a stratified Kaplan–Meier curve, chemotherapy exhibited a positive average causal effect on survival in patients with SS, whereas radiation therapy did not. The optimal subgroup for chemotherapy includes the following covariates: older than 20 years, male, large tumor (longest diameter > 5 cm), advanced stage (SEER 3), extremity location, and spindle cell type. The optimal subgroup for radiation therapy includes the following covariates: older than 20 years, male, large tumor (longest diameter > 5 cm), early stage (SEER 1), extremity location, and biphasic type.ConclusionIn this study, we identified high-risk patients whose variables include age (age > 20 years), gender, tumor size, tumor location, and poor prognosis without adjuvant treatment. Radiation therapy should be considered in the early stages for high-risk patients with biphasic types. Conversely, chemotherapy should be considered for late-stage high-risk SS patients with spindle cell types.

Inferring Protein Sequence-Function Relationships with Large-Scale Positive-Unlabeled Learning.

Machine learning can infer how protein sequence maps to function without requiring a detailed understanding of the underlying physical or biological mechanisms. It is challenging to apply existing supervised learning frameworks to large-scale experimental data generated by deep mutational scanning (DMS) and related methods. DMS data often contain high-dimensional and correlated sequence variables, experimental sampling error and bias, and the presence of missing data. Notably, most DMS data do not contain examples of negative sequences, making it challenging to directly estimate how sequence affects function. Here, we develop a positive-unlabeled (PU) learning framework to infer sequence-function relationships from large-scale DMS data. Our PU learning method displays excellent predictive performance across ten large-scale sequence-function datasets, representing proteins of different folds, functions, and library types. The estimated parameters pinpoint key residues that dictate protein structure and function. Finally, we apply our statistical sequence-function model to design highly stabilized enzymes.

Long-Term Effects of Social-Emotional Learning on Academic Skills: Evidence from a Randomized Trial of INSIGHTS

Social-Emotional Learning (SEL) programs are school-based preventive interventions that aim to improve children’s social-emotional skills and behaviors. Although meta-analytic research has shown that SEL programs implemented in early childhood can improve academic and behavioral outcomes in the short-term, there is limited work examining program effects on children’s math and language skills in the longer-term. Moreover, few studies have considered variation in impacts by children’s pre-intervention academic skills. Using an experimental design, the current study leveraged administrative data available through school records (N = 353) to examine the impacts of one SEL program—INSIGHTS into Children’s Temperament—implemented in early elementary school on math and language standardized test scores from third through sixth grade. Findings revealed positive average treatment effects on English/Language Arts (ELA) test scores in third and fourth grade, but not in fifth and sixth grade. Students who had higher academic skills at study enrollment showed lasting impacts on ELA scores in fourth, fifth, and sixth grade. There were no treatment impacts on math skills, and no variation in effects on math achievement by baseline skills. Implications are discussed.