The end of court-ordered desegregation and U.S. children's health: Quasi-experimental evidence.

School racial segregation significantly impacts racial disparities in U.S. children's health. Recently, school segregation has been increasing, partially due to Supreme Court decisions since 1991 that have made it easier for school districts to be released from court-ordered desegregation. We investigated the association of the end of court-ordered desegregation with child health using the 1997-2018 waves of the National Health Interview Survey (N=8,182 Black, 16,930 White children). We exploited quasi-random variation in the timing of school districts' releases from court orders to estimate effects on general health, body weight, mental health, and asthma, using difference-in-differences and event-study methods (including traditional and heterogeneity-robust estimators). Heterogeneity-robust difference-in-differences analyses show that release was associated with increased school segregation, improved mental health among Black children, and better self-reported health among White children. For heterogeneity-robust event-study analyses, school segregation increased steadily over time after release, with worse self-reported health and higher risk of asthma episodes among Black children 18+ years after release. Black children's mental health temporarily improved in the short term. In contrast, White children had improved self-reported health, mental health, and risk of asthma episodes in some years. Interventions to address the harms of school segregation are important for reducing racial health inequities.

Mediating pathways between neighborhood disadvantage and cardiovascular risk: Quasi-experimental evidence from a Danish refugee dispersal policy.

Research has documented that neighborhood disadvantage is associated with increased cardiovascular disease risk, but it is unclear which mechanistic pathways mediate this association across the life course. Leveraging a natural experiment in which refugees to Denmark were quasi-randomly assigned to neighborhoods across the country during 1986-1998 and using 30 years of follow-up data from population and health registers, we assessed whether and how individual-level poverty, unstable employment, and poor mental health mediate the relation between neighborhood disadvantage and the risk of hypertension, hyperlipidemia, and type 2 diabetes among Danish refugees (N= 40,811). Linear probability models using the discrete time-survival framework showed that neighborhood disadvantage was associated with increased risk of hypertension (0.05 percentage points [pp] per year [95%CI -0.00, 0.10]); hyperlipidemia (0.03 pp per year [95%CI -0.01, 0.07]), and diabetes (0.01 pp per year (95%CI -0.02, 0.03)). The Baron-Kenny product-of-coefficients method for counterfactual mediation analysis indicated that cumulative income mediated 6%-28% of the disadvantage effect on these outcomes. We find limited evidence of mediation by unstable employment and poor mental health. This study informs our theoretical understanding of the pathways linking neighborhood disadvantage with cardiovascular disease risk and identifies income security as a promising point of intervention in future research.

Advances in difference-in-differences methods for policy evaluation research.

Difference-in-differences (DiD) is a powerful, quasi-experimental research design widely used in longitudinal policy evaluations with health outcomes. However, DiD designs face several challenges to ensuring reliable causal inference, such as when policy settings are more complex. Recent economics literature has revealed that DiD estimators may exhibit bias when heterogeneous treatment effects, a common consequence of staggered policy implementation, are present. To deepen understanding of these advancements in epidemiology, in this methodologic primer, we start by presenting an overview of DiD methods. We then summarize fundamental problems associated with DiD designs with heterogeneous treatment effects and provide guidance on recently proposed heterogeneity-robust DiD estimators, which are increasingly being implemented by epidemiologists. We also extend the discussion to violations of the parallel trends assumption, which has received less attention. Last, we present results from a simulation study that compares the performance of several DiD estimators under different scenarios to enhance understanding and application of these methods.

Medicaid Expansion and Perinatal Health Outcomes: A Quasi-Experimental Study.

OBJECTIVE: There has been little evidence of the impact of preventive services during pregnancy covered under the Affordable Care Act (ACA) on birthing parent and infant outcomes. To address this gap, this study examines the association between Medicaid expansion under the ACA and birthing parent and infant outcomes of low-income pregnant people. METHODS: This study used individual-level data from the 2004-2017 annual waves of the Pregnancy Risk Assessment Monitoring System (PRAMS). PRAMS is a surveillance project of the Centers for Disease Control and Prevention and health departments that annually includes a representative sample of 1,300 to 3,400 births per state, selected from birth certificates. Birthing parents' outcomes of interest included timing of prenatal care, gestational diabetes, hypertensive disorders of pregnancy, cigarette smoking during pregnancy, and postpartum care. Infant outcomes included initiation and duration of breastfeeding, preterm birth, and birth weight. The association between ACA Medicaid expansion and the birthing parent and infant outcomes were examined using difference-in-differences estimation. RESULTS: There was no association between Medicaid expansion and the outcomes examined after correcting for multiple testing. This finding was robust to several sensitivity analyses. CONCLUSIONS FOR PRACTICE: Study findings suggest that expanded access to more complete insurance benefits with limited cost-sharing for pregnant people, a group that already had high rates of insurance coverage, did not impact the birthing parents' and infant health outcomes examined.

Evaluation of the sugar-sweetened beverage tax in Oakland, United States, 2015-2019: A quasi-experimental and cost-effectiveness study.

BACKGROUND: While a 2021 federal commission recommended that the United States government levy a sugar-sweetened beverage (SSB) tax to improve diabetes prevention and control efforts, evidence is limited regarding the longer-term impacts of SSB taxes on SSB purchases, health outcomes, costs, and cost-effectiveness. This study estimates the impact and cost-effectiveness of an SSB tax levied in Oakland, California. METHODS AND FINDINGS: An SSB tax ($0.01/oz) was implemented on July 1, 2017, in Oakland. The main sample of sales data included 11,627 beverage products, 316 stores, and 172,985,767 product-store-month observations. The main analysis, a longitudinal quasi-experimental difference-in-differences approach, compared changes in beverage purchases at stores in Oakland versus Richmond, California (a nontaxed comparator in the same market area) before and 30 months after tax implementation (through December 31, 2019). Additional estimates used synthetic control methods with comparator stores in Los Angeles, California. Estimates were inputted into a closed-cohort microsimulation model to estimate quality-adjusted life years (QALYs) and societal costs (in Oakland) from 6 SSB-associated disease outcomes. In the main analysis, SSB purchases declined by 26.8% (95% CI -39.0 to -14.7, p < 0.001) in Oakland after tax implementation, compared with Richmond. There were no detectable changes in purchases of untaxed beverages or sweet snacks or purchases in border areas surrounding cities. In the synthetic control analysis, declines in SSB purchases were similar to the main analysis (-22.4%, 95% CI -41.7% to -3.0%, p = 0.04). The estimated changes in SSB purchases, when translated into declines in consumption, would be expected to accrue QALYs (94 per 10,000 residents) and significant societal cost savings (>$100,000 per 10,000 residents) over 10 years, with greater gains over a lifetime horizon. Study limitations include a lack of SSB consumption data and use of sales data primarily from chain stores. CONCLUSIONS: An SSB tax levied in Oakland was associated with a substantial decline in volume of SSBs purchased, an association that was sustained more than 2 years after tax implementation. Our study suggests that SSB taxes are effective policy instruments for improving health and generating significant cost savings for society.

Effectiveness of Peer-Support Interventions for Smoking Cessation: A Systematic Review and Meta-analysis.

INTRODUCTION: Peer support has been recommended to promote smoking cessation, but results from prior meta-analyses have not established its efficacy. We conducted a systematic review and meta-analysis to assess current evidence and identify potential modifiers of efficacy. METHODS: Randomized controlled trials of peer-support interventions with a smoking cessation outcome were identified in January 2022 from PubMed and references listed in identified studies. The meta-analysis outcome measure was mean risk ratio (RR, 95% confidence interval [CI]) for abstinence at the longest follow-up timepoint between 3 and 9 months from baseline. Potential modifiers tested were peer smoking status (former, current, or unknown), follow-up timepoint, abstinence measure, and cumulative engagement time between peers and smokers ("dose"). Studies were assessed for risk of bias and certainty of evidence. RESULTS: We identified 16 trials, which varied in abstinence effect size (RR 0.61-3.07), sample size (23-2121), dose (41-207 minutes), and follow-up timepoint (<1-15 months). Across 15 trials with follow-up between 3 and 9 months (N = 8573 participants; 4565 intervention, 4008 control), the pooled Mantel-Haenszel RR was 1.34 (95% CI: 1.11-1.62). Effect sizes were greatest among interventions with formerly smoking peers (RR 1.43, 95% CI 1.17-1.74; five trials). We found positive effects for follow-up timepoints ≥3 months but no effect of intervention dose. The overall quality of evidence was deemed "very low." CONCLUSIONS: Peer-support interventions increased smoking abstinence. There remains a lack of consensus about how to define a peer. Intervention features such as peer smoking status appear to have explanatory power. Additional high-quality and more comparable trials are needed. IMPLICATIONS: This study reviewed the latest evidence from randomized controlled trials and found that peer-support interventions enhance smoking cessation. Efficacy varies with key intervention features such as peer smoking status and follow-up timepoint, which may be used to facilitate development of more effective peer-support interventions. Future trials and reviews would benefit from careful consideration and clear reporting of peer smoking status, length of follow-up, abstinence measures, and intervention dose.

Neighbourhood socioeconomic disadvantage and psychiatric disorders among refugees: a population-based, quasi-experimental study in Denmark.

PURPOSE: Refugees are vulnerable to psychiatric disorders because of risk factors linked to migration. Limited evidence exist on the impact of the neighbourhood in which refugee resettle. We examined whether resettling in a socioeconomically disadvantaged neighbourhood increased refugees' risk of psychiatric disorders. METHODS: This register-based cohort study included 42,067 adults aged 18 years and older who came to Denmark as refugees during 1986-1998. Resettlement policies in those years assigned refugees in a quasi-random fashion to neighbourhoods across the country. A neighbourhood disadvantage index was constructed using neighbourhood-level data on income, education, unemployment, and welfare receipt. Main outcomes were psychiatric diagnoses and psychiatric medication usage ascertained from nationwide patient and prescription drug registers, with up to 30-year follow-up. Associations of neighbourhood disadvantage with post-migration risk of psychiatric disorders were examined using Cox proportional hazards and linear probability models adjusted for individual, family, and municipality characteristics. RESULTS: The cumulative risk of psychiatric diagnoses and medication was 13.7% and 46.1%, respectively. Refugees' risk of psychiatric diagnoses and psychiatric medication usage was higher among individuals assigned to high-disadvantage compared with low-disadvantage neighbourhoods in analyses including fixed effects for assigned municipality (psychiatric diagnoses: hazard ratio (HR) = 1.14, 95% CI 1.04, 1.25; psychiatric medication: HR = 1.05, 95% CI 1.00, 1.11). Consistent results were found using linear probability models. Results for diagnostic categories and subclasses of medications suggested that the associations were driven by neurotic and stress-related disorders and use of anxiolytic medications. CONCLUSION: Resettlement in highly disadvantaged neighbourhoods was associated with an increase in refugees' risk of psychiatric disorders, suggesting that targeted placement of newly arrived refugees could benefit refugee mental health. The results contribute quasi-experimental evidence to support links between neighbourhood characteristics and health.

School racial segregation and long-term cardiovascular health among Black adults in the US: A quasi-experimental study.

BACKGROUND: Cardiovascular disease (CVD) disproportionately affects Black adults in the United States. This is increasingly acknowledged to be due to inequitable distribution of health-promoting resources. One potential contributor is inequities in educational opportunities, although it is unclear what aspects of education are most salient. School racial segregation may affect cardiovascular health by increasing stress, constraining socioeconomic opportunities, and altering health behaviors. We investigated the association between school segregation and Black adults' CVD risk. METHODS AND FINDINGS: We leveraged a natural experiment created by quasi-random (i.e., arbitrary) timing of local court decisions since 1991 that released school districts from court-ordered desegregation. We used the Panel Study of Income Dynamics (PSID) (1991 to 2017), linked with district-level school segregation measures and desegregation court order status. The sample included 1,053 Black participants who ever resided in school districts that were under a court desegregation order in 1991. The exposure was mean school segregation during observed schooling years. Outcomes included several adult CVD risk factors and outcomes. We fitted standard ordinary least squares (OLS) multivariable linear regression models, then conducted instrumental variables (IV) analysis, using the proportion of schooling years spent in districts that had been released from court-ordered desegregation as an instrument. We adjusted for individual- and district-level preexposure confounders, birth year, and state fixed effects. In standard linear models, school segregation was associated with a lower probability of good self-rated health (-0.05 percentage points per SD of the segregation index; 95% CI: -0.08, -0.03; p < 0.001) and a higher probability of binge drinking (0.04 percentage points; 95% CI: 0.002, 0.07; p = 0.04) and heart disease (0.01 percentage points; 95% CI: 0.002, 0.15; p = 0.007). IV analyses also found that school segregation was associated with a lower probability of good self-rated health (-0.09 percentage points; 95% CI: -0.17, -0.02, p = 0.02) and a higher probability of binge drinking (0.17 percentage points; 95% CI: 0.04, 0.30, p = 0.008). For IV estimates, only binge drinking was robust to adjustments for multiple hypothesis testing. Limitations included self-reported outcomes and potential residual confounding and exposure misclassification. CONCLUSIONS: School segregation exposure in childhood may have longstanding impacts on Black adults' cardiovascular health. Future research should replicate these analyses in larger samples and explore potential mechanisms. Given the recent rise in school segregation, this study has implications for policies and programs to address racial inequities in CVD.

Effects of a minimum floor Price law on cigarette use in Oakland, California: A static microsimulation model.

Tobacco minimum floor price laws (MFPLs) are a non-tax price policy that set a price below which tobacco products cannot be sold, thereby raising prices. Despite their growing interest among policy makers, little is known about the effects of local MFPLs on smoking prevalence or smoking intensity. We aimed to project the impact of a local tobacco MFPL on cigarette smoking prevalence and cigarette smoking intensity in Oakland, California, including detailed analysis of several important subpopulations. We used data collected between April 2017 and December 2019 from the California Behavioral Risk Factor Surveillance System and the National Youth Tobacco Survey to construct a static microsimulation model representative of Oakland. We projected the impact of MFPLs ranging from $8.00 to $13.00 per pack. All analyses were conducted between 2019 and 2020. With the introduction of an MFPL and assuming 15% policy evasion, mean price paid per pack was projected to increase by $1.05 to $4.69, cigarette smoking prevalence was projected to drop by 0.3% to 0.8%, and smoking intensity was projected to drop by 0.7% to 2.0% among continuing smokers. Total number of cigarettes smoked per month was projected to drop by 246,000 to 734,000 cigarettes, a 3.0% to 9.0% reduction from the current level (8.2 million cigarettes). The greatest reductions in cigarette smoking prevalence were among those aged 12 to 24-years-old, of non-Hispanic black or other race/ethnicity, and living below the federal poverty level. An MFPL in Oakland may substantially reduce cigarette use and target several important subpopulations.

Projected costs of single-payer healthcare financing in the United States: A systematic review of economic analyses.

BACKGROUND: The United States is the only high-income nation without universal, government-funded or -mandated health insurance employing a unified payment system. The US multi-payer system leaves residents uninsured or underinsured, despite overall healthcare costs far above other nations. Single-payer (often referred to as Medicare for All), a proposed policy solution since 1990, is receiving renewed press attention and popular support. Our review seeks to assess the projected cost impact of a single-payer approach. METHODS AND FINDINGS: We conducted our literature search between June 1 and December 31, 2018, without start date restriction for included studies. We surveyed an expert panel and searched PubMed, Google, Google Scholar, and preexisting lists for formal economic studies of the projected costs of single-payer plans for the US or for individual states. Reviewer pairs extracted data on methods and findings using a template. We quantified changes in total costs standardized to percentage of contemporaneous healthcare spending. Additionally, we quantified cost changes by subtype, such as costs due to increased healthcare utilization and savings due to simplified payment administration, lower drug costs, and other factors. We further examined how modeling assumptions affected results. Our search yielded economic analyses of the cost of 22 single-payer plans over the past 30 years. Exclusions were due to inadequate technical data or assuming a substantial ongoing role for private insurers. We found that 19 (86%) of the analyses predicted net savings (median net result was a savings of 3.46% of total costs) in the first year of program operation and 20 (91%) predicted savings over several years; anticipated growth rates would result in long-term net savings for all plans. The largest source of savings was simplified payment administration (median 8.8%), and the best predictors of net savings were the magnitude of utilization increase, and savings on administration and drug costs (R2 of 0.035, 0.43, and 0.62, respectively). Only drug cost savings remained significant in multivariate analysis. Included studies were heterogeneous in methods, which precluded us from conducting a formal meta-analysis. CONCLUSIONS: In this systematic review, we found a high degree of analytic consensus for the fiscal feasibility of a single-payer approach in the US. Actual costs will depend on plan features and implementation. Future research should refine estimates of the effects of coverage expansion on utilization, evaluate provider administrative costs in varied existing single-payer systems, analyze implementation options, and evaluate US-based single-payer programs, as available.

Cigarette Pack Prices and Sales Following Policy Changes in California, 2011-2018.

Objectives. To estimate the combined effect of California's Tobacco 21 law (enacted June 2016) and $2-per-pack cigarette excise tax increase (enacted April 2017) on cigarette prices and sales, compared with matched comparator states.Methods. We used synthetic control methods to compare cigarette prices and sales after the policies were enacted, relative to what we would have expected without the policy reforms. To estimate the counterfactual, we matched pre-reform covariate and outcome trends between California and control states to construct a "synthetic" California.Results. Compared with the synthetic control in 2018, cigarette prices in California were $1.89 higher ($7.86 vs $5.97; P < .001), and cigarette sales were 16.6% lower (19.9 vs 16.6 packs per capita; P < .001). This reduction in sales equates to 153.9 million fewer packs being sold between 2017 and 2018.Conclusions. California's new cigarette tax was largely passed on to consumers. The new cigarette tax, combined with the Tobacco 21 law, have contributed to a rapid and substantial reduction in cigarette consumption in California.

Peer Mentoring and Automated Text Messages for Smoking Cessation: A Randomized Pilot Trial.

INTRODUCTION: Text-messaging programs for smoking cessation, while efficacious, have high dropout rates. To address this problem, we developed and tested the feasibility and early efficacy of a peer-mentoring intervention for smoking cessation provided by former smokers. METHODS: Adult US smokers were recruited nationally into a randomized pilot trial (N = 200), comparing 6-8 weeks of automated text-messaging support (SmokefreeTXT) and automated text support plus personalized texts from a peer mentor who formerly smoked. The primary outcome was biochemically verified 7-day point-prevalence abstinence at 3 months post-quit date, assessed on an intention-to-treat basis (missing = smoking). Self-reported abstinence, program acceptability, user engagement, and user perceptions were also assessed. RESULTS: Biochemically verified abstinence at 3 months was 7.9% (8/101) in the intervention group and 3.0% (3/99) in the control group (adjusted difference 6.5, 95% CI = 0.7% to 12.3%; p = .03). Self-reported abstinence at 3 months was 23.8% (24/101) in the intervention group versus 13.1% (13/99) in the control group (adjusted difference 12.7, 95% CI = 1.2% to 24.1%; p = .03). The intervention had a positive but insignificant effect on overall satisfaction (78.3% vs. 72.9% control group, p = .55). Having a mentor did not significantly alter duration of interaction with the program nor the proportion unsubscribing, although the intervention group reset their quit date with greater frequency (p < .01) and sent more messages (p < .01). CONCLUSIONS: Peer mentoring combined with automated text messages was feasible and acceptable and increased smoking abstinence compared with automated messages alone. The results highlight the promise of this intervention approach and the need for a full-scale evaluation. IMPLICATIONS: Providing quitting assistance by automated text messaging has been shown to increase smoking abstinence. Yet, dropout rates in text-messaging programs are high. No studies have tested the effectiveness of peer mentors who are former smokers as part of a text-messaging intervention, although they represent a promising way to retain, engage, and support smokers. This randomized pilot trial suggests that peer mentors can complement automated text-messaging programs to promote smoking abstinence.

Paid Family Leave Effects on Breastfeeding: A Quasi-Experimental Study of US Policies.

Objectives. To test whether paid family leave policies in California and New Jersey improved breastfeeding practices, overall and among key subgroups.Methods. We conducted difference-in-differences analyses, comparing pre-post policy changes in California and New Jersey with changes in states where no paid family leave policies were implemented. We examined a large, diverse sample of children born during 2001 to 2013 (n = 306 266), drawn from the 2003 to 2015 National Immunization Survey waves. Outcomes included ever breastfed, breastfed exclusively at 3 and 6 months, and still breastfed at 6 and 12 months, as well as duration of any breastfeeding and exclusive breastfeeding. We examined heterogeneity in policy response by maternal characteristics.Results. Paid family leave policies resulted in a modestly greater likelihood of exclusively breastfeeding at 6 months. Subgroup analyses were mixed, although several breastfeeding outcomes were consistently improved among married, White, higher-income, and older mothers.Conclusions. Exclusive breastfeeding improved after implementation of paid family leave policies in the overall sample, and additional benefits were noted for more advantaged mothers. This contributes critical evidence to an ongoing policy discussion, suggesting that subsequent paid family leave policies should be designed to target more vulnerable mothers.

Smokers' strategic responses to sin taxes: evidence from panel data in Thailand.

In addition to quitting and cutting consumption, smokers faced with higher cigarette prices may compensate in several ways that mute the health impact of cigarette taxes. This study examines three price avoidance strategies among adult male smokers in Thailand: trading down to a lower-priced brand, buying individual sticks of cigarettes instead of packs, and substituting roll-your-own tobacco for factory-manufactured cigarettes. Using two panels of microlevel data from the International Tobacco Control Southeast Asia Study, collected in 2005 and 2006, we estimate the effects of a substantial excise tax increase implemented throughout Thailand in December 2005. We present estimates of the marginal effects and price elasticities for each of five consumer behaviors. We find that, controlling for baseline smoking characteristics, sociodemographics, and policy variables, quitting is highly sensitive to changes in cigarette prices, but so are brand choice, stick-buying, and use of roll-your-own tobacco. Neglecting such strategic responses leads to overestimates of a sin tax's health impact, and neglecting product substitution distorts estimates of the price elasticity of cigarette demand. We discuss the implications for consumer welfare and several policies that mitigate the adverse impact of consumer responses.

The heterogeneous effects of cigarette prices on brand choice in China: implications for tobacco control policy.

BACKGROUND: China has long kept its tobacco taxes below international standards. The Chinese government has cited two rationales against raising tobacco tax, namely, the unfair burden it places on low-income smokers and the ability of consumers to switch to cheaper brands. OBJECTIVE: This study examines how different socioeconomic subgroups of Chinese smokers switch brands in response to cigarette price changes. METHODS: We model smokers' choice of cigarette tier as a function of tier-specific prices. We examine heterogeneous responses to prices by estimating mixed logit models for different income and education subgroups that allow for random variation in smokers' preferences. We use data from three waves of the longitudinal International Tobacco Control China Survey, collected in six large Chinese cities between 2006 and 2009. FINDINGS: Low-income and less educated smokers are considerably more likely to switch tiers (including both up-trading and down-trading) than are their high-socioeconomic status (SES) counterparts. For those in the second-to-lowest tier, a ¥1 ($0.16, or roughly 25%) rise in prices increases the likelihood of switching tiers by 5.6% points for low-income smokers and 7.2% points for less educated smokers, compared to 1.6% and 3.0% points for the corresponding high-SES groups. Low-income and less educated groups are also more likely to trade down compared to their high-SES counterparts. CONCLUSIONS: Only a small percentage of low-income and less educated Chinese smokers switched to cheaper brands in response to price increases. Hence, the concern of the Chinese government that a cigarette tax increase will lead to large-scale brand switching is not supported by this study.

The effect of cigarette prices on brand-switching in China: a longitudinal analysis of data from the ITC China Survey.

BACKGROUND: Recent studies have found that Chinese smokers are relatively unresponsive to cigarette prices. As the Chinese government contemplates higher tobacco taxes, it is important to understand the reasons for this low response. One possible explanation is that smokers buffer themselves from rising cigarette prices by switching to cheaper cigarette brands. OBJECTIVE: This study examines how cigarette prices influence consumers' choices of cigarette brands in China. METHODS: This study uses panel data from the first three waves of the International Tobacco Control China Survey, drawn from six large cities in China and collected between 2006 and 2009. The study sample includes 3477 smokers who are present in at least two waves (8552 person-years). Cigarette brands are sorted by price into four tiers, using excise tax categories to determine the cut-off for each tier. The analysis relies on a conditional logit model to identify the relationship between price and brand choice. FINDINGS: Overall, 38% of smokers switched price tiers from one wave to the next. A ¥1 change in the price of cigarettes alters the tier choice of 4-7% of smokers. Restricting the sample to those who chose each given tier at baseline, a ¥1 increase in price in a given tier would decrease the share choosing that tier by 4% for Tier 1 and 1-2% for Tiers 2 and 3. CONCLUSIONS: China's large price spread across cigarette brands appears to alter the brand selection of some consumers, especially smokers of cheaper brands. Tobacco pricing and tax policy can influence consumers' incentives to switch brands. In particular, whereas ad valorem taxes in a tiered pricing system like China's encourage trading down, specific excise taxes discourage the practice.

Evaluation of Changes in Prices and Purchases Following Implementation of Sugar-Sweetened Beverage Taxes Across the US.

Importance: Sugar-sweetened beverage (SSB) taxes are promoted as key policies to reduce cardiometabolic diseases and other conditions, but comprehensive analyses of SSB taxes in the US have been difficult because of the absence of sufficiently large data samples and methods limitations. Objective: To estimate changes in SSB prices and purchases following SSB taxes in 5 large US cities. Design, Setting, and Participants: In this cross-sectional study with an augmented synthetic control analysis, changes in prices and purchases of SSBs were estimated following SSB tax implementation in Boulder, Colorado; Philadelphia, Pennsylvania; Oakland, California; Seattle, Washington; and San Francisco, California. Changes in SSB prices (in US dollars) and purchases (volume in ounces) in these cities in the 2 years following tax implementation were estimated and compared with control groups constructed from other cities. Changes in adjacent, untaxed areas were assessed to detect any increase in cross-border purchases. Data used for this analysis spanned from January 1, 2012, to February 29, 2020, and were analyzed between June 1, 2022, and September 29, 2023. Main Outcomes and Measures: The main outcomes were the changes in SSB prices and volume purchased. Results: Using nutritional information, 5500 unique universal product codes were classified as SSBs, according to tax designations. The sample included 26 338 stores-496 located in treated localities, 1340 in bordering localities, and 24 502 in the donor pool. Prices of SSBs increased by an average of 33.1% (95% CI, 14.0% to 52.2%; P < .001) during the 2 years following tax implementation, corresponding to an average price increase of 1.3¢ per oz and a 92% tax pass-through rate from distributors to consumers. SSB purchases declined in total volume by an average of 33.0% (95% CI, -2.2% to -63.8%; P = .04) following tax implementation, corresponding to a -1.00 price elasticity of demand. The observed price increase and corresponding volume decrease immediately followed tax implementation, and both outcomes were sustained in the months thereafter. No evidence of increased cross-border purchases following tax implementation was found. Conclusions and Relevance: In this cross-sectional study, SSB taxes led to substantial, consistent declines in SSB purchases across 5 taxed cities following price increases associated with those taxes. Scaling SSB taxes nationally could yield substantial public health benefits.

Individual and regional differences in the effects of school racial segregation on Black students' health.

Background: School racial segregation in the US has risen steadily since the 1990s, propelled by Supreme Court decisions rolling back the legacy of Brown v. Board. Quasi-experimental research has shown this resegregation harms Black students' health. However, whether individual or family characteristics (e.g., higher family incomes) are protective against segregation's health harms-or whether segregation is more damaging in regions of the US with fewer public sector investments-remains unclear. We leverage the quasi-random timing of school districts being released from Brown-era integration plans to examine heterogeneity in the association between resegregation and Black students' health. Methods & findings: We took an instrumental variables approach, using the timing of integration order releases as an instrument for school segregation and analyzing a pre-specified list of theoretically-motivated modifiers in the Panel Study of Income Dynamics. In sensitivity analyses, we fit OLS models that directly adjusted for relevant covariates. Results suggest resegregation may have been particularly harmful in the South, where districts resegregated more quickly after order releases. We find little evidence that the effects of school segregation differed across family income, gender, or age. Conclusion: The end of court-ordered integration threatens the health of Black communities-especially in the US South. Modestly higher incomes do not appear protective against school segregation's harms. Research using larger samples and alternative measures of school segregation-e.g., between districts, instead of within districts-may further our understanding of segregation's health effects, especially in Northern states.