Falsification Tests Research Articles

Unveiling the shadows: School bullying and students' ability erosions in Chinese compulsory schools

Drawing upon data from the National Children's Study of China, this research investigates the school bullying victimization and its associations with the ability erosions among students in Chinese schools. Three key findings emerge. First, results suggest that the primary factors affecting bullying victimization mainly include authoritarian parenting, limited positive social interactions on campus, adverse experiences, and exposure to teacher and peer smoking. Second, estimates indicate that bullying victimization is significantly associated with ability erosions, particularly among students from relatively advantaged backgrounds. The further Oster's test, falsification test, and reverse causality check confirm the validity of the associations and suggest some causal effect of victimization on the student outcomes. Lastly, the Oaxaca-Blinder decomposition shows that lower human capital investments derived from social interactions are the most significant contributors to the ability erosion linked to bullying victimization. These findings highlight the critical importance of social interactions both at home and in schools.

Investigating the impact of the COVID-19 pandemic on the nutritional status of infants and toddlers: insights from China

BackgroundA comprehensive understanding of the impact of the COVID-19 pandemic on childhood nutrition is crucial for devising effective mitigation strategies. However, existing knowledge regarding the pandemic’s effect on childhood nutritional status remains limited. Furthermore, research focusing on young children aged 0–3 years is scarce.MethodsLeveraging the outbreak that originated in Wuhan in Dec 2019, the epicenter of China’s first and largest outbreak, and national survey and statistical yearbook data, this study conducted a natural experimental analysis with the consideration of geographical exposure, temporal exposure and survey cohort effects to investigate the pandemic’s impacts on varying nutritional indicators of infants and toddlers aged 0–36 months. A comprehensive set of sensitivity analyses, robustness checks and falsification tests were conducted. The potential heterogeneities across socioeconomic and age groups were also examined.ResultsThe pandemic was robustly predictive of a higher weight-for-age z-score (WAZ) and length/height-for-age z-score (HAZ), and a lower likelihood of underweight. The effects of the pandemic on increasing WAZ and reducing underweight were more pronounced among children from economically disadvantaged backgrounds or aged 0–12 months. Additionally, the increasing HAZ was primarily among children from households with lower family income. Moreover, the pandemic was negatively linked to the body mass index (BMI)-for-age z-score (BAZ) of children residing in more developed cities, and positively linked to overweight/obesity among children aged 13–24 months.ConclusionsThis study adds to a more comprehensive understanding of the impact of the COVID-19 pandemic on childhood nutrition. Notably, the findings highlight that weight gain attributable to the pandemic was predominantly among vulnerable children from disadvantaged backgrounds and younger age groups, who were already at a higher risk of overweight/obesity before the pandemic. Consequently, our findings imply the necessity of greater caution to the widened gap in childhood malnutrition post-pandemic. Furthermore, the study emphasizes the importance of implementing adaptable strategies with the consideration of social justice to safeguard all children’s right to optimal growth from exogenous shocks and to achieve the children-related SDGs by 2030.

Abstract 4112546: Cannabis Legalization and Cardiovascular Hospitalizations: A Nationwide Difference-in-Differences Analysis

Background: Legal recreational cannabis sales (“legalization”) began earlier in the Western U.S. (January 2014) versus non-Western states (November 2018), providing a natural experiment to study its impact. Aim: To test the association between legalization and cardiovascular hospitalizations. Methods: Using the National Inpatient Sample (NIS), we performed a difference-in-differences analysis of the association between legalization and hospitalization rates for 6 cardiovascular diagnoses, a positive control (cannabis-related diagnoses), and 2 negative control diagnoses (opioid-related and urinary stones). We used survey-weighted Poisson regression modeling adjusted for age, sex, income, and race/ethnicity to estimate the relative change in hospitalization rates associated with each year of legalization. Results: Each year of legalization was associated with the following relative change in the hospitalization incidence rate ratio (cIRR) compared with regions that did not legalize: cannabis-related diagnoses [cIRR 1.138, 95% CI 1.066-1.214, p < 0.001], atrial fibrillation/flutter (AF) [cIRR 1.023, 95% CI 1.010-1.035, p<0.001], heart failure (HF) [cIRR 1.037, 95% CI 1.029-1.046, p < 0.001], myocardial infarction (MI) [cIRR 1.031, 95% CI 1.014-1.048, p < 0.001], ischemic stroke [cIRR 1.011, 95% CI 0.999-1.024, p=0.078], venous thromboembolism (VTE) [cIRR 1.009, 95% CI 0.999-1.020, p =0.066], and ventricular tachycardia (VT) [cIRR 1.019, 95% CI 0.993-1.046, p=0.161]. For falsification testing, there was no change in hospitalizations for urinary stones [cIRR 1.006, 95% CI 0.986-1.027, p = 0.535] or opioid-related diagnoses [cIRR 0.966, 95% CI 0.927-1.006, p = 0.091]. Conclusions: Recreational cannabis legalization was associated with increased hospitalizations for AF, HF, and MI. Further work is needed to replicate these findings in state-level analyses, ideally accounting for different cannabis formulations.

Association Between Medical Debt and Vaccine Uptake in the USA, 2021-2022.

Many individuals do not receive recommended vaccines, increasing infectious disease morbidity and mortality. It is unknown whether the financial practices of US healthcare institutions contribute to vaccine hesitancy. To determine whether medical debt is associated with low vaccine uptake. Cross-sectional analysis of the association between medical debt and vaccine receipt. 56,373 adult participants in the 2021-2022 National Health Interview Survey. Presence of medical debt at the time of survey administration. We used logistic regression models to assess whether medical debt was associated with recent vaccine receipt, adjusting for sociodemographic, health, and access-to-care variables. We performed a sensitivity analysis restricted to individuals with health insurance and conducted a falsification test of the hypothesis that current medical debt would not be associated with remote prior vaccination (i.e., > 1year prior, likely before debt acquisition). Individuals with medical debt were less likely than those without such debt to receive any recent vaccine (adjusted odds ratio [aOR] 0.83, 95% confidence interval [CI] 0.76-0.91), including influenza vaccination (aOR 0.83, 95% CI 0.75-0.91) or COVID-19 vaccination (aOR 0.79, 95% CI 0.69-0.91). Analyses limited to insured individuals had similar findings (aOR for any recent vaccination 0.79, 95% CI 0.72-0.88). In the falsification test, current medical debt was not associated with remote prior vaccination (aOR 1.04, 95% CI 0.93-1.16). Current medical debt is associated with lower likelihood of recent vaccine receipt in both insured and uninsured individuals. Policies that minimize medical debt may improve vaccine coverage.

CEOs' narcissism and opportunistic insider trading

Narcissism is a multifaceted personality trait that profoundly influences individuals' cognition, emotions, and actions. This study investigates the relationship between narcissistic CEOs and their engagement in opportunistic insider trading. Utilizing a quantitative measure of CEOs' narcissism derived from textual analysis, we find that CEOs with a higher level of narcissism engage in opportunistic insider trading more intensely. To mitigate endogeneity concerns, we employ various rigorous approaches, including matching, instrumental variable, Heckman's two-step sample selection model, and falsification tests. Through cross-sectional analysis, we find that the impact of CEOs' narcissism on opportunistic insider trading is more pronounced among CEOs with limited legal knowledge, facing weaker external and internal monitoring pressure, working at larger firms, and being male. In addition, we demonstrate that the insider trades of narcissistic CEOs are less profitable and less informative than those of non-narcissistic CEOs, as evidenced by subsequent stock performance.

The Impact of Mobile Money on Perception about Cash and Financial Inclusion: Micro-Level Evidence from Uganda

The debate about the future of cash has recently intensified as technology innovations in the financial sector accelerate digital payments and the creation of new, digital forms of money. Several countries have embraced initiatives towards cashless or cash-light payments. In Sub-Saharan Africa (SSA), mobile money has dominated the list of digital payment innovations. These innovations hold the potential to alter individuals’ behaviour towards cash. Will mobile money render cash less dominant in Africa? Can it promote financial inclusion? We address these questions by exploring individual-level data for Uganda, a country in an African region that pioneered the mobile money revolution in the world. We use the Propensity Score Matching method to robustly compare mobile money users and non-users across various indicators that capture individuals’ perceptions about cash, and the extent to which they remit, save, and borrow money. We present the first evidence that mobile money users, compared to non-users, are more likely to perceive cash as risky and less likely to prefer carrying large amounts of cash. We also confirm that mobile money users are more likely to receive and send remittances, save, and borrow. They also save and borrow larger amounts. The estimation methodology used in the paper, robustness analysis, and a falsification test help reduce potential concerns about selection bias and reverse causality. Two implications emerge from the findings. First, the rapid expansion of fintech technologies in Africa is likely to reduce, although slowly, the demand for and usage of cash over time. Second, the expansion of fintech technologies could help promote financial inclusion in Africa

Toilet construction under the Swachh Bharat Mission and infant mortality in India

Improvement of water and sanitation conditions may reduce infant mortality, particularly in countries like India where open defecation is highly prevalent. We conducted a quasi-experimental study to investigate the association between the Swachh Bharat Mission (SBM)—a national sanitation program initiated in 2014—and infant (IMR) and under five mortality rates (U5MR) in India. We analyzed data from thirty-five Indian states and 640 districts spanning 10 years (2011–2020), with IMR and U5MR per thousand live births as the outcomes. Our main exposure was the district-level annual percentage of households that received a constructed toilet under SBM. We mapped changes in IMR and U5MR and toilet access at the district level over time. We fit two-way fixed effects regression models controlling for sociodemographic, wealth, and healthcare-related confounders at the district-level to estimate the association between toilets constructed and child mortality. Toilet access and child mortality have a historically robust inverse association in India. Toilets constructed increased dramatically across India following the implementation of SBM in 2014. Results from panel data regression models show that districts with > 30% toilets constructed under SBM corresponds with 5.3 lower IMR (p < 0.05), and 6.8 lower U5MR (p < 0.05). Placebo, falsification tests and robustness checks support our main findings. The post-SBM period in India exhibited accelerated reductions in infant and child mortality compared to the pre-SBM years. Based on our regression estimates, the provision of toilets at-scale may have contributed to averting approximately 60,000–70,000 infant deaths annually. Our findings show that the implementation of transformative sanitation programs can deliver population health benefits in low- and middle-income countries.

Valuing the Future: Changing Time Horizons and Policy Preferences

AbstractThe short time horizons of citizens are a prominent explanation for why governments fail to tackle significant long-term public policy problems. Evidence for the influence of time horizons is mixed, complicated by the difficulty of determining how attitudes would differ if individuals were more concerned about the future. This paper approaches the challenge by leveraging a personal experience that leads people to place more value on the future: parenthood. The analysis compares new parents with otherwise similar individuals using a matched difference-in-differences design with a three-wave panel. The results show that parenthood increases support for stopping climate change. Falsification tests and two survey experiments suggest that longer time horizons explain part of this shift in support. Not only are scholars right to emphasize the role of individual time horizons, but changing valuations of the future offer a new way to understand how policy preferences evolve.

Lottery jackpot winnings and retail trading in the neighborhood

We use lottery jackpot winnings in a neighborhood as an exogenous shock to investing in stocks. We find that retail investors whose brokerages are near the stores that sell winning tickets buy more stocks than their counterparts after the shock. These purchases lead to lower returns. We use a survey to identify the behavioral factors like regretfulness and probability weighting that are the main drivers of our findings. Moreover, these investors tend to buy more lottery-like stocks, but the shock does not affect their selling decisions. Finally, we perform several falsification tests and robustness checks and find consistent results.

Partner wealth and audit quality: evidence from the United States

AbstractUsing the market values of audit partners’ houses as a measure of their personal wealth, we find that wealthier U.S. partners provide higher-quality audits, as evidenced by fewer material restatements, fewer material SEC comment letters, and higher audit fees. A battery of falsification tests shows that these findings are not driven by the matching of wealthier partners with clients with higher financial reporting quality. Our additional analyses suggest two explanations: greater personal wealth both incentivizes partners to exert more effort in delivering high-quality audits and reveals partners’ audit competence.

The Role of Public Development Banks During the Pandemic: Impact Evaluation of BICE's Innovative Credit Response

ABSTRACT The global COVID-19 pandemic triggered a renewed impetus for the countercyclical role of development banks, marked by widespread adoption of diverse instruments to mitigate its impact. Argentina's development bank (BICE, Banco de Inversión y Comercio Exterior, specialized in loan for long term investment, responded to the 2020 health and economic crises implementing a working capital loan program. Amidst a lack of substantial evidence on the efficacy of similar counter-cyclical interventions, we employed a quasi-experimental methodology, incorporating Propensity Score Matching (PSM) and Fixed Effects (FE) estimations, to evaluate the program's impact. Our results demonstrate that firms benefiting from the loan maintained employment levels, in stark contrast to a nearly 6 per cent decrease for those without it. The program effectively mitigated the employment impact of the transient shock. Robustness checks, along with falsification tests, bolster our identification strategy. Complementary findings emphasize that the program's success lies in providing credit during adverse conditions, when private sector credit contracts. This insight, rather than the exceptional terms of the credit, offers a crucial lesson for the future.

The local driving safety effect of motorcycle restrictions: Evidence from China

Motorcycles are a highly unstable element that impacts road traffic safety due to insufficient safety protection structures and poor maneuverability. The rapid increase in their use has exacerbated the severity of crash-related fatalities and injuries. While some countries have implemented motorcycle restrictions to address this phenomenon, the causal effect of such policies on reducing the severity of injuries from accidents requires further research. This study employs a difference-in-differences approach to estimate the causal effect of motorcycle restrictions in China on the severity of road crash injuries. The results indicate a significant reduction in the likelihood of fatal or severe injuries occurring in crashes. Specifically, in regions with motorcycle restrictions, the probability of crashes resulting in fatal or severe injuries decreased by 2.9% on average. The results remain robust following placebo and falsification tests and excluding confounding effects. Heterogeneity analysis reveals that motorcycle restrictions primarily affect male drivers and drivers with urban hukou, with no significant differences in effects across drivers of different age groups. Overall, the findings indicate that motorcycle restrictions reduce the number of motorcycles on the road and decrease the probability of motorcycle drivers being at fault in crashes, signifying improved driver behavior and effectively lowering crash severity.

The Value of Clean Air: Evidence from Chinese Housing Markets

This paper studies the value of clean air by analyzing the effect of China’s clean air policy. By exploiting the cross-city variation in the timing of policy implementation and using a panel dataset of 280 cities from 2003 to 2018, we find that the clean air policy boosts housing prices by 4.4%. The finding is robust to a series of potential issues, functional misspecifications, and falsification tests. In addition, we examine whether the effect varies across different price-tier cities and changes over time, and we find evidence of such heterogeneous and dynamic effects.

A study on the benefit incidence of a place-based education fee reduction program: Evidence from a local housing market in China

This paper studies an Education Fee Reduction and Exemption Program for preschool childcare in Jinan, China, to explore the benefit incidence among different stakeholders by observing how housing prices and rents change in response to this program and by employing a method of difference-in-differences combined with boundary discontinuity. The empirical findings indicate that the housing prices in the experimental area rose by 5–7 percent while the rents rose by 10–13 percent due to the capitalization effects of this equalization program. Falsification tests are conducted using artificial boundaries and fake policy implementation dates. A back-of-the-envelope welfare analysis demonstrates that a considerable portion of the program's benefits is offset by house price increases for new home buyers and rent increases for tenants, with significant distributional implications for different stakeholders.

Infant safe havens

AbstractI estimate whether the ability to anonymously surrender an infant to a safe haven site such as a hospital, police station, or fire station in the United States affects child well‐being. By analyzing variation in state safe haven policies, I find safe haven laws significantly increase infant foster care entrance. I further find suggestive evidence of safe havens reducing infant deaths. The mortality effects are immediate but subside over time, implying infants have been relinquished when their alternative was not death from abuse or abandonment. Robustness checks and falsification tests support these findings.

Gender composition of children and sanitation behavior in India

Open defecation has been linked to various environmental and public health issues and has gained significant policy attention. Investing in better sanitation has also been advocated to provide women with privacy and protection from harassment. Nonetheless, previous research has shown that because of son-biased preferences, households in India underinvest in outcomes for their female children. Linking the gender composition of children to the sanitation behavior in Indian households, I find that households increase toilet ownership in the presence of female children by 5% in urban and 2.5% in rural areas, respectively. These results are robust to various empirical specifications, falsification tests, and bounding analysis to test for omitted-variable bias. Various heterogeneity analyses suggest that the decline in open defecation in response to having a female child is driven by households living in regions with a higher prevalence gender-based harassment and weaker law and order. These findings provide new evidence that differences in the gender composition of households create differential incentives to adopt toilets, which can be harnessed to reduce open defecation in India.

Using the global randomization test as a Mendelian randomization falsification test for the exclusion restriction assumption

Mendelian randomization may give biased causal estimates if the instrument affects the outcome not solely via the exposure of interest (violating the exclusion restriction assumption). We demonstrate use of a global randomization test as a falsification test for the exclusion restriction assumption. Using simulations, we explored the statistical power of the randomization test to detect an association between a genetic instrument and a covariate set due to (a) selection bias or (b) horizontal pleiotropy, compared to three approaches examining associations with individual covariates: (i) Bonferroni correction for the number of covariates, (ii) correction for the effective number of independent covariates, and (iii) an r2 permutation-based approach. We conducted proof-of-principle analyses in UK Biobank, using CRP as the exposure and coronary heart disease (CHD) as the outcome. In simulations, power of the randomization test was higher than the other approaches for detecting selection bias when the correlation between the covariates was low (r2 < 0.1), and at least as powerful as the other approaches across all simulated horizontal pleiotropy scenarios. In our applied example, we found strong evidence of selection bias using all approaches (e.g., global randomization test p < 0.002). We identified 51 of the 58 CRP genetic variants as horizontally pleiotropic, and estimated effects of CRP on CHD attenuated somewhat to the null when excluding these from the genetic risk score (OR = 0.96 [95% CI: 0.92, 1.00] versus 0.97 [95% CI: 0.90, 1.05] per 1-unit higher log CRP levels). The global randomization test can be a useful addition to the MR researcher’s toolkit.

Association of copayments with healthcare utilization and expenditures among Medicaid enrollees with a substance use disorder

BackgroundThe purpose of this study was to examine the association between copayments and healthcare utilization and expenditures among Medicaid enrollees with substance use disorders. MethodsThis study used claims data (2020−2021) from a private insurer participating in Arkansas's Medicaid expansion. We compared service utilization and expenditures for enrollees in different Medicaid program structures with varying copayments. Enrollees with incomes above 100 % FPL (N = 10,240) had copayments for substance use treatment services while enrollees below 100 % FPL (N = 2478) did not. Demographic, diagnostic, utilization, and cost information came from claims and enrollment information. The study identified substance use and clinical comorbidities using claims from July through December 2020 and evaluated utilization and costs in 2021. Generalized linear models (GLM) estimated outcomes using single equation and two-part modeling. A gamma distribution and log link were used to model expenditures, and negative binomial models were used to model utilization. A falsification test comparing behavioral health telemedicine utilization, which had no cost sharing in either group, assessed whether differences in the groups may be responsible for observed findings. ResultsSubstance use enrollees with copayments were less likely to have a substance use or behavioral health outpatient (−0.04 PP adjusted; p = 0.001) or inpatient visit (−0.04 PP; p = 0.001) relative to their counterparts without copayments, equal to a 17 % reduction in substance use or behavioral health outpatient services and a nearly 50 % reduction in inpatient visits. The reduced utilization among enrollees with a copayment was associated with a significant reduction in total expenses ($954; p = 0.001) and expenses related to substance use or behavioral health services ($532; p = 0.001). For enrollees with at least one behavioral health visit, there were no differences in outpatient or inpatient utilization or expenditures between enrollees with and without copayments. Copayments had no association with non-behavioral health or telemedicine services where neither group had cost sharing. ConclusionCopayments serve as an initial barrier to substance use treatment, but are not associated with the amount of healthcare utilization conditional on using services. Policy makers and insurers should consider the role of copayments for treatment services among enrollees with substance use disorders in Medicaid programs.

Currency flotation and dividend policies: Evidence from China's central parity reform

AbstractExploiting the 2015 central parity reform in China, we examine whether and how currency flotation affects corporate payout policies. The reform shifted China's currency regime from a crawling peg to the US dollar to partial flotation, significantly increasing its currency risk. We find that firms with high foreign currency exposures reduced their cash dividends postreform relative to firms with low foreign currency exposures. The dividend reduction is more pronounced for firms with less financial hedging or less financial flexibility before the reform. Firms display asymmetrical responses to foreign exchange gains versus losses. Specifically, while firms cut cash dividends when experiencing foreign exchange losses, they do not increase cash dividends when obtaining foreign exchange gains. A falsification test shows no changes in firms’ stock dividends that do not involve cash flows. Overall, our study shows that currency flotation, through increasing currency risks, dampens firms’ cash dividends.

MRSamePopTest: introducing a simple falsification test for the two-sample mendelian randomisation ‘same population’ assumption

Two-sample MR is an increasingly popular method for strengthening causal inference in epidemiological studies. For the effect estimates to be meaningful, variant-exposure and variant-outcome associations must come from comparable populations. A recent systematic review of two-sample MR studies found that, if assessed at all, MR studies evaluated this assumption by checking that the genetic association studies had similar demographics. However, it is unclear if this is sufficient because less easily accessible factors may also be important. Here we propose an easy-to-implement falsification test. Since recent theoretical developments in causal inference suggest that a causal effect estimate can generalise from one study to another if there is exchangeability of effect modifiers, we suggest testing the homogeneity of variant-phenotype associations for a phenotype which has been measured in both genetic association studies as a method of exploring the ‘same-population’ test. This test could be used to facilitate designing MR studies with diverse populations. We developed a simple R package to facilitate the implementation of our proposed test. We hope that this research note will result in increased attention to the same-population assumption, and the development of better sensitivity analyses.