Adopting electric school buses in the United States: Health and climate benefits.

Electric school buses have been proposed as an alternative to reduce the health and climate impacts of the current U.S. school bus fleet, of which a substantial share are highly polluting old diesel vehicles. However, the climate and health benefits of electric school buses are not well known. As they are substantially more costly than diesel buses, assessing their benefits is needed to inform policy decisions. We assess the health benefits of electric school buses in the United States from reduced adult mortality and childhood asthma onset risks due to exposure to ambient fine particulate matter (PM2.5). We also evaluate climate benefits from reduced greenhouse-gas emissions. We find that replacing the average diesel bus in the U.S. fleet in 2017 with an electric bus yields $84,200 in total benefits. Climate benefits amount to $40,400/bus, whereas health benefits amount to $43,800/bus due to 4.42*10-3 fewer PM2.5-attributable deaths ($40,000 of total) and 7.42*10-3 fewer PM2.5-attributable new childhood asthma cases ($3,700 of total). However, health benefits of electric buses vary substantially by driving location and model year (MY) of the diesel buses they replace. Replacing old, MY 2005 diesel buses in large cities yields $207,200/bus in health benefits and is likely cost-beneficial, although other policies that accelerate fleet turnover in these areas deserve consideration. Electric school buses driven in rural areas achieve small health benefits from reduced exposure to ambient PM2.5. Further research assessing benefits of reduced exposure to in-cabin air pollution among children riding buses would be valuable to inform policy decisions.

Sex-specific scaling of leaf phosphorus vs. nitrogen under unequal reproductive requirements in Eurya japonica, a dioecious plant.

PREMISE: Previous work searching for sexual dimorphism has largely relied on the comparison of trait mean vectors between sexes in dioecious plants. Whether trait scaling (i.e., the ratio of proportional changes in covarying traits) differs between sexes, along with its functional significance, remains unclear. METHODS: We measured 10 vegetative traits pertaining to carbon, water, and nutrient economics across 337 individuals (157 males and 180 females) of the diocious species Eurya japonica during the fruiting season in eastern China. Piecewise structural equation modeling was employed to reveal the scaling relationships of multiple interacting traits, and multivariate analysis of (co)variance was conducted to test for intersexual differences. RESULTS: There was no sexual dimorphism in terms of trait mean vectors across the 10 vegetative traits in E. japonica. Moreover, most relationships for covarying trait pairs (17 out of 19) exhibited common scaling slopes between sexes. However, the scaling slopes for leaf phosphorus (P) vs. nitrogen (N) differed between sexes, with 5.6- and 3.0-fold increases of P coinciding with a 10-fold increase of N in male and female plants, respectively. CONCLUSIONS: The lower ratio of proportional changes in P vs. N for females likely reflects stronger P limitation for their vegetative growth, as they require greater P investments in fruiting. Therefore, P vs. N scaling can be a key avenue allowing for sex-specific strategic optimization under unequal reproductive requirements. This study uncovers a hidden aspect of secondary sex character in dioecious plants, and highlights the use of trait scaling to understand sex-defined economic strategies.

Benefit-Cost Analysis for Earthquake-Resilient Building Design and Retrofit: State of the Art and Future Research Needs.

This paper reviews the state of the art in using benefit-cost analysis (BCA) to inform earthquake risk reduction decisions by building owners and policymakers. The goal is to provide a roadmap for the application and future development of BCA methods and tools for earthquake risk reduction. Our review covers three earthquake risk reduction measures: adopting up-to-date building codes for new construction, designing new buildings to exceed code requirements, and retrofitting deficient existing buildings. We highlight the factors that influence the cost-effectiveness of building design and retrofit, as well as tactics for increasing the cost-effectiveness of risk reduction strategies. We also present BCA results, methods, and data sources used in the literature to help researchers and practitioners design and conduct a reliable and robust BCA study. In the process, we develop a set of opportunities and challenges for applying BCA to new areas of research, as well as key gaps and limitations in current BCA approaches, including further investigation of above-code design, incorporation of code implementation and enforcement into BCA, quantification of environmental benefits of seismic retrofits, and optimization of seismic retrofits with energy upgrades. Overall, our review provides practical guidance and useful insights into BCA with the goal of increasing the earthquake resilience and economic efficiency of buildings in the United States.

Constructing time-invariant dynamic surveillance rules for optimal monitoring schedules.

Dynamic surveillance rules (DSRs) are sequential surveillance decision rules informing monitoring schedules in clinical practice, which can adapt over time according to a patient's evolving characteristics. In many clinical applications, it is desirable to identify and implement optimal time-invariant DSRs, where the parameters indexing the decision rules are shared across different decision points. We propose a new criterion for DSRs that accounts for benefit-cost tradeoff during the course of disease surveillance. We develop two methods to estimate the time-invariant DSRs optimizing the proposed criterion, and establish asymptotic properties for the estimated parameters of biomarkers indexing the DSRs. The first approach estimates the optimal decision rules for each individual at every stage via regression modeling, and then estimates the time-invariant DSRs via a classification procedure with the estimated time-varying decision rules as the response. The second approach proceeds by optimizing a relaxation of the empirical objective, where a surrogate function is utilized to facilitate computation. Extensive simulation studies are conducted to demonstrate the superior performances of the proposed methods. The methods are further applied to the Canary Prostate Active Surveillance Study (PASS).

Health and Economic Evaluation of Vaccination Against Pertussis in China: A 40-Year Analysis.

OBJECTIVES: This study aimed to evaluate the health and economic impact of diphtheria, tetanus, whole-cell pertussis vaccine (DTwP) and diphtheria-tetanus-acellular pertussis vaccine (DTaP) vaccination on pertussis prevention and control in China during the 40 years from 1978 to 2017. METHODS: We conducted cost-benefit analyses with a decision tree model populated with historical vaccination coverage levels and pertussis incidence and mortality data from before 1978 and during 1978 to 2017. We modeled 40 birth cohorts from birth until death. Costs and benefits were estimated from direct cost and societal perspectives (direct and indirect costs). Costs and benefits were adjusted to 2017 US dollars (USD), and future values were discounted at a 3% annual rate. We calculated net benefit values (net savings) and benefit-cost ratios of pertussis vaccination of children younger than 5 years. We conducted sensitivity analyses by varying key parameters within plausible ranges. RESULTS: Without DTwP and DTaP vaccination, there would be an estimated 115.76 million pertussis cases and 426 650 pertussis deaths in the 40 cohorts. With DTwP/DTaP vaccination, pertussis cases and deaths were decreased by an estimated 92.57% and 97.43%, saving 46 987.81 million USD in direct costs and 82 013.37 million USD from societal perspective. Pertussis vaccination program costs were 2168.76 million USD and 3961.28 million USD from direct cost and societal perspectives. Benefit-cost ratios were 21.67:1 from the direct cost perspective and 20.70:1 from the societal perspective. Sensitivity analyses showed the results to be robust. CONCLUSIONS: Over the lifetime of 40 birth cohorts, China's immunization program is preventing 93% of pertussis cases and 97% of pertussis deaths, resulting in substantial savings to the healthcare system and society.

The benefits and costs of U.S. employer COVID-19 vaccine mandates.

In 2021, the Biden Administration issued mandates requiring COVID-19 vaccinations for U.S. federal employees and contractors and for some healthcare and private sector workers. These mandates have been challenged in court; some have been halted or delayed. However, their costs and benefits have not been rigorously appraised. This study helps fill that gap. We estimate the direct costs and health-related benefits that would have accrued if these vaccination requirements had been implemented as intended. Compared with the January 2022 vaccination rates, we find that the mandates could have led to 15 million additional vaccinated individuals, increasing the overall proportion of the fully vaccinated U.S. population from 64% to 68%. The associated net benefits depend on the subsequent evolution of the pandemic-information unavailable ex ante to analysts or policymakers. In scenarios involving the emergence of a novel, more transmissible variant, against which vaccination and previous infection offer moderate protection, the estimated net benefits are potentially large. They reach almost $20,000 per additional vaccinated individual, with more than 20,000 total deaths averted over the 6-month period assessed. In scenarios involving a fading pandemic, existing vaccination-acquired or infection-acquired immunity provides sufficient protection, and the mandates' benefits are unlikely to exceed their costs. Thus, mandates may be most useful when the consequences of inaction are catastrophic. However, we do not compare the effects of mandates with alternative policies for increasing vaccination rates or for promoting other protective measures, which may receive stronger public support and be less likely to be overturned by litigation.

Benefit-cost analysis of becoming certified pollinator friendly.

Despite significant drop in pollinator abundance, no studies exist on the benefits and costs of pollinator conservation in the public domain. An in-person survey was conducted at three large, public US universities to estimate benefits to become Bee Campus USA certified. We test whether different types of reminders on existing student sustainability fees affect Willingness to Pay. Costs of achieving this certification per university were obtained. Net Present Value demonstrates that the net benefits to each school are largely positive, except under the most restrictive assumption. Information reminders of existing fees lead to little change in support of pollinator conservation.

Exploring epidemic voluntary vaccinating behavior based on information-driven decisions and benefit-cost analysis.

A complex dynamic interplay exists between epidemic transmission and vaccination, which is significantly influenced by human behavioral responses. We construct a research framework combining both the function modeling of the cumulative global COVID-19 information and limited individuals' information processing capacity employing the Gompertz model for growing processes. Meanwhile, we built a function representing the decision to get vaccinated following benefit-cost analysis considered the choices made by people in each scenario have an influence from altruism, free-riding and immunity escaping capacity. Through the mean-field calculation analysis and using a fourth-order Runge-Kutta method with constant step size, we obtain plots from numerical simulations. We found that only when the total number of infectious individuals proves sufficient to reach and exceed a certain level will the individuals face a better trade-off in determining whether to get vaccinated against the diseases based on that information. Besides, authoritative media have a higher decisive influence and efforts should be focused on extending the duration of vaccine protection, which is beneficial to inhibit the outbreaks of epidemics. Our work elucidates that reducing the negative payoff brought about by the free-riding behavior for individuals or improving the positive payoff from the altruistic motivation helps to control the disease in cultures that value social benefits, vaccination willingness is generally stronger. We also note that at a high risk of infection, the decision of vaccination is highly correlated with global epidemic information concerning COVID-19 infection, while at times of lower risk, it depends on the game theoretic vaccine strategy. The findings demonstrate that improving health literacy, ensuring open and transparent information on vaccine safety and efficacy as a public health priority can be an effective strategy for mitigating inequalities in health education, as well as alleviating the phenomenon that immunity escaping abilities is more likely to panic by populations with high levels of education. In addition, prosocial nudges are great ways to bridge these immunity gaps that can contribute to implementing government public health control measures, creating a positive feedback loop.

Iron Fortification through Universal Distribution of Double-Fortified Salt Can Increase Wages and Be Cost-Effective: An Ex-Ante Modeling Study in India.

BACKGROUND: The alleviation of iron deficiency through iron supplementation has not effectively reduced anemia in India, mainly due to low compliance. Food fortification with iron is considered a viable alternative, and the provision of double-fortified salt (DFS; with iron and iodine) has been mandated in public health programs. Limited evidence exists on its benefit-cost ratio. OBJECTIVE: In this study we sought to estimate the economic benefit in terms of increased wages in relation to introduction of DFS in reduction of anemia and the cost of doing so. METHODS: The economic benefit of introducing DFS in India was derived using a series of mathematical, statistical, and econometric models using data from national surveys capturing earnings and dietary iron intake of the population. Anemia status was predicted from data on dietary intake, sanitation, and for women, menstrual losses. The impact of iron deficiency anemia (IDA) on wages was estimated using a Heckman Selection model and 2-stage least squares procedure. Benefit of DFS was estimated through increased wages attributed to anemia reduction compared with its cost. RESULTS: Men and women with IDA had lower wages (by 25.9%, 95% CI: 11.3, 38.1; and by 3.9%, 95% CI: 0.0, 7.7, respectively) than those without IDA. Additional iron intake through DFS was predicted to reduce prevalence of IDA (from 10.6% to 0.7% in men and 23.8% to 20.9% in women). The economic benefit-cost ratio of introducing DFS at a national level was estimated to be 4.2:1. CONCLUSIONS: Iron fortification delivered through DFS under a universal program can improve wages and be sufficiently cost-effective for its implementation at scale in India.

Economic analysis of financial incentives for smoking cessation during pregnancy and postpartum.

Higgins and colleagues' recently-completed randomized controlled trial and pooled data with 4 related trials of smoking cessation in pregnant women in Vermont (USA) showed that abstinence-contingent financial incentives (FI) increased abstinence over control conditions from early pregnancy through 24-weeks postpartum. Control conditions were best practices (BP) alone in the recent trial and payments provided independent of smoking status (noncontingently) in the others. This paper reports economic analyses of abstinence-contingent FI. Merging trial results with maternal and infant healthcare costs from all Vermont Medicaid deliveries in 2019, we computed incremental cost-effectiveness ratios (ICERs) for quality-adjusted life years (QALYs) and compared them to established thresholds. The healthcare sector cost (±standard error) of adding FI to BP averaged $634.76 ± $531.61 per participant. Based on this trial, the increased probability per BP + FI participant of smoking abstinence at 24-weeks postpartum was 3.17%, the cost per additional abstinent woman was $20,043, the incremental health gain was 0.0270 ± 0.0412 QALYs, the ICER was $23,511/QALY gained, and the probabilities that BP + FI was very cost-effective (ICER≤$65,910) and cost-effective (ICER≤$100,000) were 67.9% and 71.0%, respectively. Based on the pooled trials, the corresponding values were even more favorable-8.89%, $7138, 0.0758 ± 0.0178 QALYs, $8371/QALY, 98.6% and 99.3%, respectively. Each dollar invested in abstinence-contingent FI over control smoking-cessation programs yielded $4.20 in economic benefits in the recent trial and $11.90 in the pooled trials (very favorable benefit-cost ratios). Medicaid and commercial insurers may wish to consider covering financial incentives for smoking abstinence as a cost-effective service for pregnant beneficiaries who smoke. Trial Registration: ClinicalTrials.gov identifier: NCT02210832.

Cost/benefit assessment of green infrastructure: Spatial scale effects on uncertainty and sensitivity.

Green infrastructure (GI) is becoming a common solution to mitigate stormwater-related problems. Given the uncertain costs of GI relative to other stormwater management strategies, stakeholders investing in GI need performance-analysis tools that consider the full suite of benefits and the impacts of uncertainty to help justify GI expenditures. This study provides a quantitative and comparative analysis of GI benefits, including nutrient uptake from stormwater and air pollutant deposition. Economic costs and benefits of GI are assessed using two metrics, benefit-cost ratios (BCRs) and nutrient removal costs, at three scales: household, subwatershed, and watershed scale. Results from a case study in the state of Maryland show that the costs of nutrient uptake at the subwatershed scale can be lower than those at either the watershed or household scales. Moreover, rain gardens are far more efficient in stormwater treatment at the household scale in comparison to watershed scale, for which large-scale dry or wet basins are more efficient. Using a BCR metric, smaller subwatersheds show more promise, while using a nutrient removal cost metric indicates that upstream subwatersheds are more suitable for stormwater treatment. The results also show that implementation of GI at all potential pervious locations does not necessarily increase nutrient removal costs and that self-installation of rain gardens greatly reduces nutrient removal costs. Finally, the results show that using numerous small-sized rain garden practices in front of residential buildings yields lower nutrient removal costs in comparison to permeable pavements placed in parking lots and commercial buildings.

Cost benefit analysis of clinical pharmacist interventions in medical intensive care unit in Palestine medical complex: Prospective interventional study.

Background: Clinical pharmacy services in the critical health care settings have expanded dramatically.Study problem.Clinical pharmacy services have limited implementation in Palestine. Many intensive care units (ICUs) patients do not get the intended beneficial effects of their treatment due to treatment related problems and their consequent cost burden. Aim: To evaluate the impact of the clinical pharmacist interventions on costs of care and safety of patient by assessing treatment related problems among medical ICUs patients in Palestine. Methodology: A prospective interventional study was conducted at medical ICU of the major public hospital in Ramallah city over a 4-month period (between September and December 2020). Patients were randomly assigned to either an intervention or a control group (With / without clinical pharmacist involvement). Treatment related problems were identified in both study groups by the clinical pharmacist, but interventions were only provided to the intervention group. The total economic benefit included both cost savings from intervention and cost avoidance from preventable adverse drug events (ADEs) resulted from CP interventions. The primary outcomes with the clinical pharmacist interventions were net benefit and benefit to cost ratio, which were calculated using previously published methodologies and adjusted to the Palestinian settings. The analysis of CP interventions acceptance by physicians was performed. Results: During the 4-month study period, the 117 patients admitted to the ICU were included into the analysis; 66 patients in the intervention group and 51 in the control group. The interventions made by a clinical pharmacist resulted in direct cost saving of NIS8,990.05 ($2799.63) and cost avoidance of NIS22,087.5 ($ 6878.37). Translated into a net savings of NIS188.35 ($58.65) per intervention and NIS470 ($146.36) per patient. Comparison of benefits (NIS31,077.55) ($9678.00) and costs (NIS19,043.928) ($5930.55) indicate a net economic benefit to the institution of (NIS 12,033.623) ($3747.44) and a benefit cost ratio of 1.63. Conclusion: Integrating a clinical pharmacist in the ICU team was investment that resulted in benefits in term of cost saving and cost avoidance.

Quantification and characterization of recovered materials in the cycle of the informal household electronic waste dismantling in Buriram province, Thailand: A challenge towards sustainable management and circular economy.

The numerous amount of electronic waste (e-waste) has not been managed effectively resulting informal dismantling sites are being expanded in Thailand. The government attempts to improve the efficiency of an integrated e-waste management system, but baseline data of e-waste stream in informal sectors are insufficient. This research aimed to investigate the inflow and outflow of the materials throughout the informal e-waste dismantling processes at the well-known second-largest community in Buriram province during 2017-2018. To describe the quantities of dismantled materials, a material flow analysis was performed. The overall amount of e-waste taken to the community was estimated to be in the range of 1593-12,943 tonnes year-1. Valuable materials could be recovered at more than 90% (by mass) from fans, refrigerators, washing machines, microwaves and air conditioners. The amount of e-waste residue that the local administrative organization had to handle was up to 1144 tonnes year-1. The quantitative data retrieved from this study could provide a satisfactory equation for estimating the amount of separated valuable and non-valuable materials. Recyclable materials from dismantling have an economic incentive, e-waste dismantlers in a small and large household group that can earn approximately 798 and 1262 USD month-1 income, respectively. The notable e-waste characterization and quantification of recovered materials would be useful for improving the potential circular flow of e-waste in Thailand.

Approaches for estimating benefits and costs of interventions in plant biosecurity across invasion phases.

Nonnative plant pests cause billions of dollars in damages. It is critical to prevent or reduce these losses by intervening at various stages of the invasion process, including pathway risk management (to prevent pest arrival), surveillance and eradication (to counter establishment), and management of established pests (to limit damages). Quantifying benefits and costs of these interventions is important to justify and prioritize investments and to inform biosecurity policy. However, approaches for these estimations differ in (1) the assumed relationship between supply, demand, and prices, and (2) the ability to assess different types of direct and indirect costs at invasion stages, for a given arrival or establishment probability. Here we review economic approaches available to estimate benefits and costs of biosecurity interventions to inform the appropriate selection of approaches. In doing so, we complement previous studies and reviews on estimates of damages from invasive species by considering the influence of economic and methodological assumptions. Cost accounting is suitable for rapid decisions, specific impacts, and simple methodological assumptions but fails to account for feedbacks, such as market adjustments, and may overestimate long-term economic impacts. Partial equilibrium models consider changes in consumer and producer surplus due to pest impacts or interventions and can account for feedbacks in affected sectors but require specialized economic models, comprehensive data sets, and estimates of commodity supply and demand curves. More intensive computable general equilibrium models can account for feedbacks across entire economies, including capital and labor, and linkages among these. The two major considerations in choosing an approach are (1) the goals of the analysis (e.g., consideration of a single pest or intervention with a limited range of impacts vs. multiple interventions, pests or sectors), and (2) the resources available for analysis such as knowledge, budget and time.

Recent Advances in Probabilistic Dose-Response Assessment to Inform Risk-Based Decision Making.

Paradoxically, risk assessments for the majority of chemicals lack any quantitative characterization as to the likelihood, incidence, or severity of the risks involved. The relatively few cases where "risk" is truly quantified are based on either epidemiologic data or extrapolation of experimental animal cancer bioassay data. The paucity of chemicals and health endpoints for which such data are available severely limits the ability of decisionmakers to account for the impacts of chemical exposures on human health. The development by the World Health Organization International Programme on Chemical Safety (WHO/IPCS) in 2014 of a comprehensive framework for probabilistic dose-response assessment has opened the door to a myriad of potential advances to better support decision making. Building on the pioneering work of Evans, Hattis, and Slob from the 1990s, the WHO/IPCS framework provides both a firm conceptual foundation as well as practical implementation tools to simultaneously assess uncertainty, variability, and severity of effect as a function of exposure. Moreover, such approaches do not depend on the availability of epidemiologic data, nor are they limited to cancer endpoints. Recent work has demonstrated the broad feasibility of such approaches in order to estimate the functional relationship between exposure level and the incidence or severity of health effects. While challenges remain, such as better characterization of the relationship between endpoints observed in experimental animal or in vitro studies and human health effects, the WHO/IPCS framework provides a strong basis for expanding the breadth of risk management decision contexts supported by chemical risk assessment.

The Benefits and Costs of Cybersecurity Risk Reduction: A Dynamic Extension of the Gordon and Loeb Model.

This article develops a dynamic extension of the classic model of cybersecurity investment formulated by Gordon and Loeb. In this dynamic model, results are influenced by the rate at which cybersecurity assets depreciate and the rate of return on investment. Depreciation costs are lower in the dynamic model than is implicitly assumed in the classic model, while the rate-of-return threshold is higher. On balance, the user cost of cybersecurity assets is lower in the dynamic model than is implicitly assumed in the classic model. This difference increases the economically efficient size of the cybersecurity system in value terms, increasing the efficient level of risk reduction.

Do the Benefits of COVID-19 Policies Exceed the Costs? Exploring Uncertainties in the Age-VSL Relationship.

Numerous analyses of the benefits and costs of COVID-19 policies have been completed quickly as the crisis has unfolded. The results often largely depend on the approach used to value mortality risk reductions, typically expressed as the value per statistical life (VSL). Many analyses rely on a population-average VSL estimate; some adjust VSL for life expectancy at the age of death. We explore the implications of theory and empirical studies, which suggest that the relationship between age and VSL is uncertain. We compare the effects of three approaches: (1) an invariant population-average VSL; (2) a constant value per statistical life-year (VSLY); and (3) a VSL that follows an inverse-U pattern, peaking in middle age. We find that when applied to the U.S. age distribution of COVID-19 deaths, these approaches result in average VSL estimates of $10.63 million, $4.47 million, and $8.31 million. We explore the extent to which applying these estimates alters the conclusions of frequently cited analyses of social distancing, finding that they significantly affect the findings. However, these analyses do not address other characteristics of COVID-19 deaths that may increase or decrease the VSL estimates. Examples include the health status and income level of those affected, the size of the risk change, and the extent to which the risk is dreaded, uncertain, involuntarily incurred, and outside of one's control. The effects of these characteristics and their correlation with age are uncertain; it is unclear whether they amplify or diminish the effects of age on VSL.

Introduction to Special Issue on Risk Assessment, Economic Evaluation, and Decisions.

Integrating risk assessment, economic evaluation, and uncertainty to inform policy decisions is a core challenge to risk analysis. In September 2019, the Harvard Center for Risk Analysis, with support from the Society for Risk Analysis Economics and Benefits Analysis Specialty Group and others, convened a workshop to address this issue. The workshop built in part on the recommendations of the 2009 National Research Council report, Science and Decisions: Advancing Risk Assessment. It honored John S. Evans, whose thoughtful and innovative teaching and scholarship have significantly advanced thinking on these issues. This special issue features a profile of Dr. Evans and nine articles that build on work presented at the workshop.

Long-term Impacts and Benefit-Cost Analysis of the Communities That Care Prevention System at Age 23, 12 Years After Baseline.

This study estimated sustained impacts and long-term benefits and costs of the Communities That Care (CTC) prevention system, implemented and evaluated in a longitudinal cluster-randomized trial involving 24 communities in seven states. Analyses utilized reports from a longitudinal panel of 4407 participants, followed since the study's baseline in grade 5, with most recent follow-up 12 years later at age 23. Impacts on lifetime abstinence from primary outcomes of substance use and antisocial behavior were estimated using generalized linear mixed Poisson regression analysis, adjusted for individual and community-level covariates. Possible cascading effects on 4-year college completion, major depressive disorder, and generalized anxiety disorder through age 23 were evaluated as secondary outcomes. CTC had a statistically significant global effect on primary outcomes and also on combined primary and secondary outcomes. Among primary outcomes, point estimates suggested absolute improvements in lifetime abstinence of 3.5 to 6.1% in the intervention arm and relative improvements of 13 to 55%; 95% confidence intervals revealed some uncertainty in estimates. Among secondary outcomes, 4-year college completion was 1.9% greater among young adults from intervention communities, a 20% relative improvement. Mental health outcomes were approximately the same across trial arms. Although CTC had small sustained effects through age 23, benefit-cost analyses indicated CTC was reliably cost beneficial, with a net present value of $7152 (95% credible interval: $1253 to $15,268) per participant from primary impacts and $17,919 ($306 to $39,186) when secondary impacts were also included. It remained cost beneficial even when impacts were adjusted downward due to the involvement of CTC's developer in the trial. Findings suggest that broader dissemination of CTC could improve public health and individual lives in the long term and generate positive net benefits to society.

Quantifying the social benefits and costs of reducing phosphorus pollution under climate change.

Excess phosphorus loading to waterbodies has led to increasing frequency and severity of harmful algal blooms, negatively impacting economic activity and human health. While interventions to improve water quality can create large societal benefits, these investments are costly and the value of benefits is often unknown. Understanding the social and economic impacts of reduced phosphorus loading is critical for developing effective land use policies and for generating public and political support for these initiatives. Here, we quantify the social benefits and costs of improving water quality in Lake Champlain under a range of phosphorus reduction and climate change scenarios between 2016 and 2050. We use statistical models to link water quality outputs from an established integrated assessment model with three categories of benefits: tourism expenditures, property sales, and avoided human health impacts. We estimate the costs of reducing phosphorus loading using data reported by the State of Vermont. We find that under the most aggressive phosphorus reduction scenario, the total benefits of improved water quality are $55 to $60 million between 2016 and 2050. Over this 35 year time horizon, the combined benefits do not outweigh the costs under any scenario. If the time horizon is extended to 2100 or beyond, however, the benefits may exceed the costs if the applied discount rate is less than 3%. Importantly, we almost certainly underestimate the value of clean water, due to the omission of other types of benefits. Despite this uncertainty, our study provides a tractable framework for disentangling the complex relationships between water quality and human well-being, and illuminates the value of reductions in phosphorus loading to society.