Trusting the Science

Kevin Lewis

July 26, 2021

The Impact of the COVID-19 Pandemic and Policy Responses on Excess Mortality
Virat Agrawal et al.
NBER Working Paper, June 2021


As a way of slowing COVID-19 transmission, many countries and U.S. states implemented shelter-in-place (SIP) policies. However, the effects of SIP policies on public health are a priori ambiguous as they might have unintended adverse effects on health. The effect of SIP policies on COVID-19 transmission and physical mobility is mixed. To understand the net effects of SIP policies, we measure the change in excess deaths following the implementation of SIP policies in 43 countries and all U.S. states. We use an event study framework to quantify changes in the number of excess deaths after the implementation of a SIP policy. We find that following the implementation of SIP policies, excess mortality increases. The increase in excess mortality is statistically significant in the immediate weeks following SIP implementation for the international comparison only and occurs despite the fact that there was a decline in the number of excess deaths prior to the implementation of the policy. At the U.S. state-level, excess mortality increases in the immediate weeks following SIP introduction and then trends below zero following 20 weeks of SIP implementation. We failed to find that countries or U.S. states that implemented SIP policies earlier, and in which SIP policies had longer to operate, had lower excess deaths than countries/U.S. states that were slower to implement SIP policies. We also failed to observe differences in excess death trends before and after the implementation of SIP policies based on pre-SIP COVID-19 death rates.

Transparent communication about negative features of COVID-19 vaccines decreases acceptance but increases trust
Michael Bang Petersen et al.
Proceedings of the National Academy of Sciences, 20 July 2021


During the rapid development and rolling out of vaccines against COVID-19, researchers have called for an approach of “radical transparency,” in which vaccine information is transparently disclosed to the public, even if negative information can decrease vaccine uptake. Consistent with theories about the psychology of conspiracy beliefs, these calls predict that a lack of transparency may reduce trust in health authorities and may facilitate the spread of conspiracy theories, which may limit the long-term capabilities of health authorities during and after the pandemic. On the basis of preregistered experiments conducted on large, representative samples of Americans and Danes (N > 13,000), the current study contrasts the effects of vague vaccine communication with transparent communication, which discloses either positive or negative vaccine features. The evidence demonstrates that transparent negative communication may indeed harm vaccine acceptance here and now but that it increases trust in health authorities. Furthermore, the alternative of vague, reassuring communication does not increase vaccine acceptance either and leads to both lower trust and higher endorsement of conspiracy theories.

Biden, COVID and Mental Health in America
David Blanchflower & Alex Bryson
NBER Working Paper, July 2021


Using US Census Household Pulse Survey data for the period April 2020 to June 2021 we track the evolution of the mental health of nearly 2.3 million Americans during the COVID pandemic. We find anxiety, depression and worry peaked in November 2020, coinciding with the Presidential election. The taking of prescription drugs for mental health conditions peaked two weeks later in December 2020. Mental health improved subsequently such that by April 2021 it was better than it had been a year previously. The probability of having been diagnosed with COVID did not rise significantly in the first half of 2021 but COVID infection rates were higher among the young than the old. COVID diagnoses were significantly lower in States that had voted for Biden in the Presidential Election. The probability of vaccination rose with age, was considerably higher in Biden states, and rose precipitously over the period among the young and old. Anxiety was higher among people in Biden states, whether they had been diagnosed or not, and whether they were vaccinated or not. The association between anxiety and depression and having had COVID was not significant in Biden or Trump states but being vaccinated was associated with lower anxiety and depression, with the effect being larger in Biden states. Whilst being in paid work was associated with lower anxiety, worry and depression and was associated with higher vaccination rates, it also increased the probability of having had COVID.

The Type I interferon antiviral gene program is impaired by lockdown and preserved by caregiving
Steven Cole et al.
Proceedings of the National Academy of Sciences, 20 July 2021


Previous research has linked perceived social isolation (loneliness) to reduced antiviral immunity, but the immunologic effects of the objective social isolation imposed by pandemic “shelter in place” (SIP) policies is unknown. We assessed the immunologic impact of SIP by relocating 21 adult male rhesus macaques from 2,000-m2 field cage communities of 70 to 132 other macaques to 2 wk of individual housing in indoor shelters. SIP was associated with 30% to 50% reductions in all circulating immune cell populations (lymphocytes, monocytes, and granulocytes), down-regulation of Type I interferon (IFN) antiviral gene expression, and a relative up-regulation of CD16− classical monocytes. These effects emerged within the first 48 h of SIP, persisted for at least 2 wk, and abated within 4 wk of return to social housing. A subsequent round of SIP in the presence of a novel juvenile macaque showed comparable reductions in circulating immune cell populations but reversal of Type I IFN reductions and classical monocyte increases observed during individual SIP. Analyses of lymph node tissues showed parallel up-regulation of Type I IFN genes and enhanced control of viral gene expression during juvenile-partnered SIP compared to isolated SIP. These results identify a significant adverse effect of SIP social isolation on antiviral immune regulation in both circulating immune cells and lymphoid tissues, and they suggest a potential behavioral strategy for ameliorating gene regulatory impacts (but not immune cell declines) by promoting prosocial engagement during SIP.

Doctors' and Nurses' Social Media Ads Reduced Holiday Travel and COVID-19 Infections: A Cluster Randomized Controlled Trial
Emily Breza et al.
NBER Working Paper, July 2021


During the COVID-19 epidemic, many health professionals started using mass communication on social media to relay critical information and persuade individuals to adopt preventative health behaviors. Our group of clinicians and nurses developed and recorded short video messages to encourage viewers to stay home for the Thanksgiving and Christmas Holidays. We then conducted a two-stage clustered randomized controlled trial in 820 counties (covering 13 States) in the United States of a large-scale Facebook ad campaign disseminating these messages. In the first level of randomization, we randomly divided the counties into two groups: high intensity and low intensity. In the second level, we randomly assigned zip codes to either treatment or control such that 75% of zip codes in high intensity counties received the treatment, while 25% of zip codes in low intensity counties received the treatment. In each treated zip code, we sent the ad to as many Facebook subscribers as possible (11,954,109 users received at least one ad at Thanksgiving and 23,302,290 users received at least one ad at Christmas). The first primary outcome was aggregate holiday travel, measured using mobile phone location data, available at the county level: we find that average distance travelled in high-intensity counties changed by -0.993 percentage points (95% CI -1.616, -0.371, p-value 0.002) the three days before each holiday. The second primary outcome was COVID-19 infection at the zip-code level: COVID-19 infections recorded in the two-week period starting five days post-holiday declined by 3.5 percent (adjusted 95% CI [-6.2 percent, -0.7 percent], p-value 0.013) in intervention zip codes compared to control zip codes.

Has Mortality Risen Disproportionately for the Least Educated?
Adam Leive & Christopher Ruhm
Journal of Health Economics, forthcoming


We examine whether the least educated population groups experienced the worst mortality trends at the beginning of the 21st century by measuring changes in mortality across education quartiles. We document sharply differing gender patterns. Among women, mortality trends improved fairly monotonically with education. Conversely, male trends for the lowest three education quartiles were often similar. For both sexes, the gap in mortality between the top 25 percent and the bottom 75 percent is growing. However, there are many groups for whom these patterns are reversed – with better experiences for the less educated – or where the differences are statistically indistinguishable.

Is Recreational Marijuana a Gateway to Harder Drug Use and Crime?
Joseph Sabia et al.
NBER Working Paper, July 2021


Recreational marijuana laws (RMLs), which legalize the possession of small quantities of marijuana for recreational use, have been adopted by 18 states and the District of Columbia. Opponents argue that RML-induced increases in marijuana consumption will serve as a “gateway” to harder drug use and crime. Using data covering the period 2000-2019 from a variety of national sources (the National Survey of Drug Use and Health, the Uniform Crime Reports, the National Vital Statistics System, and the Treatment Episode Data Set) this study is the first to comprehensively examine the effects of legalizing recreational marijuana on hard drug use, arrests, drug overdose deaths, suicides, and treatment admissions. Our analyses show that RMLs increase adult marijuana use and reduce drug-related arrests over an average post-legalization window of three to four years. There is little evidence to suggest that RML-induced increases in marijuana consumption encourage the use of harder substances or violent criminal activity.

The effects of false identification laws on underage alcohol-related traffic fatalities
Erik Nesson & Vinish Shrestha
Health Economics, forthcoming


We examine the effects of policies aimed at restricting the use of false identification to purchase alcohol on traffic fatalities involving alcohol-impaired underage drivers. We find that the implementation of policies that incentivize alcohol retailers to adopt ID scanners reduces traffic fatalities from accidents involving 16–18 year old drivers with a BAC >0, but we do not find that similar policies like vertical ID laws lead to statistically significant changes in traffic fatalities involving underage impaired drivers. A back-of-the-envelope calculation suggests that if all remaining states passed ID scanner laws, the reduction in underage alcohol-related fatal accidents would generate over $400 million in annual economic benefits.

Young Adult Cannabis Use Disorder Treatment Admissions Declined as Past Month Cannabis Use Increased in the U.S.: An Analysis of States by Year, 2008-2017
Jeremy Mennis, Gerald Stahler & Thomas McKeon
Addictive Behaviors, forthcoming

Objective: This short communication reports on the association of annual measures of young adult (age 18-24) past month cannabis use with cannabis use disorder (CUD) treatment admissions by state in the U.S. from 2008-2017.

Methods: Annual data on percentage of past month cannabis use and the total number of CUD treatment admissions among young adults were acquired for each state from SAMHSA NSDUH and TEDS-A data sets. For each state, the correlation over time between cannabis use and treatment admissions rate was calculated and visualized in a choropleth map. Fixed-effects regression, where effects are fixed by state, was used to investigate the association of cannabis use with treatment admissions rate.

Results: In 38 out of 50 states, including seven out of the eight states legalizing recreational cannabis during the study period, as young adult cannabis use increased, treatment admissions declined. Cannabis use is significantly and negatively associated with treatment admissions (β=-7.21, 95% CI =-11.88, -2.54), even after controlling for health insurance coverage, criminal justice referral, treatment center availability, and cannabis legalization status.

White matter plasticity in healthy older adults: The effects of aerobic exercise
Andrea Mendez Colmenares et al.
NeuroImage, forthcoming


White matter deterioration is associated with cognitive impairment in healthy aging and Alzheimer's disease. It is critical to identify interventions that can slow down white matter deterioration. So far, clinical trials have failed to demonstrate the benefits of aerobic exercise on the adult white matter using diffusion Magnetic Resonance Imaging. Here, we report the effects of a 6-month aerobic walking and dance interventions (clinical trial NCT01472744) on white matter integrity in healthy older adults (n = 180, 60–79 years) measured by changes in the ratio of calibrated T1- to T2-weighted images (T1w/T2w). Specifically, the aerobic walking and social dance interventions resulted in positive changes in the T1w/T2w signal in late-myelinating regions, as compared to widespread decreases in the T1w/T2w signal in the active control. Notably, in the aerobic walking group, positive change in the T1w/T2w signal correlated with improved episodic memory performance. Lastly, intervention-induced increases in cardiorespiratory fitness did not correlate with change in the T1w/T2w signal. Together, our findings suggest that white matter regions that are vulnerable to aging retain some degree of plasticity that can be induced by aerobic exercise training. In addition, we provided evidence that the T1w/T2w signal may be a useful and broadly accessible measure for studying short-term within-person plasticity and deterioration in the adult human white matter.

Opioids and Organs: How Overdoses Affect the Supply and Demand for Organ Transplants
Stacy Dickert-Conlin et al.
Georgia State University Working Paper, June 2021


As the incidence of fatal drug overdose has quadrupled in the U.S. in the past two decades, patients awaiting organ transplants may be unintended beneficiaries. We use Vital Statistics mortality data, merged with data on the universe of transplant candidates and recipients in the U.S. from the Scientific Registry of Transplant Recipients, to study the extent to which the growth in opioid-related deaths affects the supply of deceased organ donors and transplants. Using two separate identification strategies, we find that opioid-related deaths led to more than 22,000 organ transplants in the U.S. between 2008 and 2018. Although we detect little evidence of demand responses to opioid-induced organ supply shocks, we find that transplant centers are increasingly recovering organs from overdose victims for transplant, with the association between opioid-related deaths and organ donors more than doubling between 2008 and 2018. We also present evidence that transplant candidates appear to be more willing to use organs from those who died of opioid-related causes when organ shortages are relatively severe.

The Dynamics of the Smoking Wage Penalty
Michael Darden, Julie Hotchkiss & Melinda Pitts
Journal of Health Economics, forthcoming


Cigarette smokers earn significantly less than nonsmokers, but the magnitude of the smoking wage gap and the pathways by which it originates are unclear. Proposed mechanisms often focus on spot differences in employee productivity or employer preferences, neglecting the dynamic nature of human capital development and addiction. In this paper, we formulate a dynamic model of young workers as they transition from schooling to the labor market, a period in which the lifetime trajectory of wages is being developed. We estimate the model with data from the National Longitudinal Survey of Youth, 1997 Cohort, and we simulate the model under counterfactual scenarios that isolate the contemporaneous effects of smoking from dynamic differences in human capital accumulation and occupational selection. Results from our preferred model, which accounts for unobserved heterogeneity in the joint determination of smoking, human capital, labor supply, and wages, suggest that continued heavy smoking in young adulthood results in a wage penalty at age 30 of 15.9 and 15.2 for women and men, respectively. These differences are much smaller than the raw difference in means in wages at age 30. We show that the contemporaneous effect of heavy smoking net of any life-cycle effects explains 62.9 of the female smoking wage gap but only 20.4 of the male smoking wage gap.

Does Transportation Mean Transplantation? Impact of New Airline Routes on Sharing of Cadaveric Kidneys
Guihua Wang, Ronghuo Zheng & Tinglong Dai
Management Science, forthcoming


Every year, nearly 5,000 patients die while waiting for kidney transplants, and yet an estimated 3,500 procured kidneys are discarded. Such a polarized coexistence of dire scarcity and massive wastefulness has been mainly driven by insufficient pooling of cadaveric kidneys across geographic regions. Although numerous policy initiatives are aimed at broadening organ pooling, they rarely account for a key friction — efficient airline transportation, ideally direct flights, is necessary for long-distance sharing, because of the time-sensitive nature of kidney transplantation. Conceivably, transplant centers may be reluctant to accept kidney offers from far-off locations without direct flights. In this paper, we estimate the effect of the introduction of new airline routes on broader kidney sharing. By merging the U.S. airline transportation and kidney transplantation data sets, we create a unique sample tracking (1) the evolution of airline routes connecting all the U.S. airports and (2) kidney transplants between donors and recipients connected by these airports. We estimate the introduction of a new airline route increases the number of shared kidneys by 7.3%. We also find a net increase in the total number of kidney transplants and a decrease in the organ discard rate with the introduction of new routes. Notably, the posttransplant survival rate remains largely unchanged, although average travel distance increases after the introduction of new airline routes. Our results are robust to alternative empirical specifications and have important implications for improving access to the U.S. organ transplantation system.


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