scholarly journals Towards Principled Unskewing: Viewing 2020 Election Polls Through a Corrective Lens from 2016

2021 ◽  
Author(s):  
Michael Isakov ◽  
Shiro Kuriwaki

We apply the concept of the data defect index to study the potential impact of systematic errors on the 2020 pre-election polls in 12 presidential battleground states. We investigate the impact under the hypothetical scenarios that (1) the magnitude of the underlying nonresponse bias correlated with supporting Donald Trump is similar to that of the 2016 polls, (2) the pollsters’ ability to correct systematic errors via weighting has not improved significantly, and (3) turnout levels remain similar to 2016. Because survey weights are crucial for our investigations but are often not released, we adopt two approximate methods under different modeling assumptions. Under these scenarios, which may be far from reality, our models shift Trump’s estimated two-party voteshare by a percentage point in his favor in the median battleground state, and increases twofold the uncertainty around the voteshare estimate.

2017 ◽  
Vol 33 (3) ◽  
pp. 857-871 ◽  
Author(s):  
Jaki McCarthy ◽  
James Wagner ◽  
Herschel Lisette Sanders

Abstract Nonresponse rates have been growing over time leading to concerns about survey data quality. Adaptive designs seek to allocate scarce resources by targeting specific subsets of sampled units for additional effort or a different recruitment protocol. In order to be effective in reducing nonresponse, the identified subsets of the sample need two key features: 1) their probabilities of response can be impacted by changing design features, and 2) once they have responded, this can have an impact on estimates after adjustment. The National Agricultural Statistics Service (NASS) is investigating the use of adaptive design techniques in the Crops Acreage, Production, and Stocks Survey (Crops APS). The Crops APS is a survey of establishments which vary in size and, hence, in their potential impact on estimates. In order to identify subgroups for targeted designs, we conducted a simulation study that used Census of Agriculture (COA) data as proxies for similar survey items. Different patterns of nonresponse were simulated to identify subgroups that may reduce estimated nonresponse bias when their response propensities are changed.


BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e043863
Author(s):  
Jingyuan Wang ◽  
Ke Tang ◽  
Kai Feng ◽  
Xin Lin ◽  
Weifeng Lv ◽  
...  

ObjectivesWe aim to assess the impact of temperature and relative humidity on the transmission of COVID-19 across communities after accounting for community-level factors such as demographics, socioeconomic status and human mobility status.DesignA retrospective cross-sectional regression analysis via the Fama-MacBeth procedure is adopted.SettingWe use the data for COVID-19 daily symptom-onset cases for 100 Chinese cities and COVID-19 daily confirmed cases for 1005 US counties.ParticipantsA total of 69 498 cases in China and 740 843 cases in the USA are used for calculating the effective reproductive numbers.Primary outcome measuresRegression analysis of the impact of temperature and relative humidity on the effective reproductive number (R value).ResultsStatistically significant negative correlations are found between temperature/relative humidity and the effective reproductive number (R value) in both China and the USA.ConclusionsHigher temperature and higher relative humidity potentially suppress the transmission of COVID-19. Specifically, an increase in temperature by 1°C is associated with a reduction in the R value of COVID-19 by 0.026 (95% CI (−0.0395 to −0.0125)) in China and by 0.020 (95% CI (−0.0311 to −0.0096)) in the USA; an increase in relative humidity by 1% is associated with a reduction in the R value by 0.0076 (95% CI (−0.0108 to −0.0045)) in China and by 0.0080 (95% CI (−0.0150 to −0.0010)) in the USA. Therefore, the potential impact of temperature/relative humidity on the effective reproductive number alone is not strong enough to stop the pandemic.


BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Bimandra A. Djaafara ◽  
Charles Whittaker ◽  
Oliver J. Watson ◽  
Robert Verity ◽  
Nicholas F. Brazeau ◽  
...  

Abstract Background As in many countries, quantifying COVID-19 spread in Indonesia remains challenging due to testing limitations. In Java, non-pharmaceutical interventions (NPIs) were implemented throughout 2020. However, as a vaccination campaign launches, cases and deaths are rising across the island. Methods We used modelling to explore the extent to which data on burials in Jakarta using strict COVID-19 protocols (C19P) provide additional insight into the transmissibility of the disease, epidemic trajectory, and the impact of NPIs. We assess how implementation of NPIs in early 2021 will shape the epidemic during the period of likely vaccine rollout. Results C19P burial data in Jakarta suggest a death toll approximately 3.3 times higher than reported. Transmission estimates using these data suggest earlier, larger, and more sustained impact of NPIs. Measures to reduce sub-national spread, particularly during Ramadan, substantially mitigated spread to more vulnerable rural areas. Given current trajectory, daily cases and deaths are likely to increase in most regions as the vaccine is rolled out. Transmission may peak in early 2021 in Jakarta if current levels of control are maintained. However, relaxation of control measures is likely to lead to a subsequent resurgence in the absence of an effective vaccination campaign. Conclusions Syndromic measures of mortality provide a more complete picture of COVID-19 severity upon which to base decision-making. The high potential impact of the vaccine in Java is attributable to reductions in transmission to date and dependent on these being maintained. Increases in control in the relatively short-term will likely yield large, synergistic increases in vaccine impact.


2021 ◽  
Vol 56 (2) ◽  
pp. 113-119
Author(s):  
Xinming Xia ◽  
Wan-Hsin Liu

AbstractThis paper analyses how China’s investments in Germany have developed over time and the potential impact of the COVID-19 pandemic in this regard, based on four different datasets, including our own survey in mid-2020. Our analysis shows that Germany is currently one of the most attractive investment destinations for Chinese investors. Chinese state-owned enterprises have played an important role as investors in Germany — particularly in large-scale projects. The COVID-19 pandemic has had some negative but rather temporary effects on Chinese investments in Germany. Germany is expected to stay attractive to Chinese investors who seek to gain access to advanced technologies and know-how in the future.


2019 ◽  
Vol 28 (1) ◽  
pp. 180-190
Author(s):  
Ireneusz Wlodarczyk

AbstractWe computed the impact solutions of the potentially dangerous Near Earth Asteroid (NEA) 2001 BB16 based on 47 optical observations from January 20.08316 UTC, 2001, through February 09.15740 UTC, 2016, and one radar observation from January 19.90347 UTC, 2016. We used two methods to sample the starting Line of Variation (LOV). First method, called thereafter LOV1, with the uniform sampling of the LOV parameter, out to LOV = 5 computing 3000 virtual asteroids (VAs) on both sides of the LOV, which gives 6001 VAs and propagated their orbits to JD2525000.5 TDT=February 12, 2201. We computed the non-gravitational parameterA2=(34.55±7.38)·10–14 au/d2 for nominal orbit of 2001 BB16 and possible impacts with the Earth until 2201. For potential impact in 2195 we find A2=20.0·10−14 au/d2. With a positive value of A2, 2001 BB16 can be prograde rotator. Moreover, we computed Lyapunov Time (LT) for 2001 BB16, which for all VAs, has a mean value of about 25 y. We showed that impact solutions, including the calculated probability of a possible collision of a 2001 BB16 asteroid with the Earth depends on how to calculate and take into account the appropriate gravitational model, including the number of perturbing massive asteroids. In some complicated cases, it may depend also on the number of clones calculated for a given sigma LOV1. The second method of computing the impact solutions, called thereafter LOV2, is based on a non-uniformly sampling of the LOV. We showed that different methods of sampling the LOV can give different impact solutions, but all computed dates of possible impacts of the asteroid 2001 BB16 with the Earth occur in accordance at the end of the 22nd century.


Author(s):  
E Gaztanaga ◽  
S J Schmidt ◽  
M D Schneider ◽  
J A Tyson

Abstract We test the impact of some systematic errors in weak lensing magnification measurements with the COSMOS 30-band photo-z Survey flux limited to Iauto < 25.0 using correlations of both source galaxy counts and magnitudes. Systematic obscuration effects are measured by comparing counts and magnification correlations. We use the ACS-HST catalogs to identify potential blending objects (close pairs) and perform the magnification analyses with and without blended objects. We find that blending effects start to be important (∼ 0.04 mag obscuration) at angular scales smaller than 0.1 arcmin. Extinction and other systematic obscuration effects can be as large as 0.10 mag (U-band) but are typically smaller than 0.02 mag depending on the band. After applying these corrections, we measure a 3.9σ magnification signal that is consistent for both counts and magnitudes. The corresponding projected mass profiles of galaxies at redshift z ≃ 0.6 (MI ≃ −21) is Σ = 25 ± 6M⊙h3/pc2 at 0.1 Mpc/h, consistent with NFW type profile with M200 ≃ 2 × 1012M⊙h/pc2. Tangential shear and flux-size magnification over the same lenses show similar mass profiles. We conclude that magnification from counts and fluxes using photometric redshifts has the potential to provide complementary weak lensing information in future wide field surveys once we carefully take into account systematic effects, such as obscuration and blending.


Author(s):  
Emilia Grzędzicka ◽  
Jiří Reif

AbstractPlant invasions alter bird community composition worldwide, but the underlying mechanisms still require exploration. The investigation of feeding guild structure of bird communities can be informative in respect to the potential impact of invasion features on the availability of food for birds. For this purpose, we focused on determining the influence of the invasive Sosnowsky’s Hogweed Heracleum sosnowskyi on the abundance of birds from various feeding guilds. In spring and summer 2019, birds were counted three times on 52 pairs of sites (control + Heracleum) in southern Poland, at various stages of Sosnowsky’s Hogweed development (i.e. sprouting, full growth and flowering, all corresponding to respective bird counts). We have shown that the presence of invader negatively affected the abundance of birds from all feeding guilds. However, a closer examination of the invaded sites uncovered that responses of particular guilds differed in respect to development stages expressed by a set of characteristics of the invader. Ground and herb insectivores were more common on plots with a higher number of the invader, while the abundance of bush and tree insectivores was negatively correlated with hogweeds’ height. Granivores were not affected by the invader’s features, while the abundance of omnivores was negatively related to the number of flowering hogweeds. Besides showing the general negative impact of the invader on different feeding guilds, our research has shown that certain aspects of Sosnowsky’s Hogweed invasion may support or depress occurrence of different birds on invaded plots. Knowledge of these aspects may facilitate our capacity for coping with challenges the invasive plants put in front of bird conservationists.


2019 ◽  
Vol 4 (5) ◽  
pp. e001786 ◽  
Author(s):  
Marta Schaaf ◽  
Emily Maistrellis ◽  
Hana Thomas ◽  
Bergen Cooper

During his first week in office, US President Donald J Trump issued a presidential memorandum to reinstate and broaden the reach of the Mexico City policy. The Mexico City policy (which was in place from 1985–1993, 1999–2000 and 2001–2009) barred foreign non-governmental organisations (NGOs) that received US government family planning (FP) assistance from using US funds or their own funds for performing, providing counselling, referring or advocating for safe abortions as a method of FP. The renamed policy, Protecting Life in Global Health Assistance (PLGHA), expands the Mexico City policy by applying it to most US global health assistance. Thus, foreign NGOs receiving US global health assistance of nearly any type must agree to the policy, regardless of whether they work in reproductive health. This article summarises academic and grey literature on the impact of previous iterations of the Mexico City policy, and initial research on impacts of the expanded policy. It builds on this analysis to propose a hypothesis regarding the potential impact of PLGHA on health systems. Because PLGHA applies to much more funding than it did in its previous iterations, and because health services have generally become more integrated in the past decade, we hypothesise that the health systems impacts of PLGHA could be significant. We present this hypothesis as a tool that may be useful to others’ and to our own research on the impact of PLGHA and similar exogenous overseas development assistance policy changes.


Open Heart ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. e000943 ◽  
Author(s):  
Leopold Ndemnge Aminde ◽  
Linda J Cobiac ◽  
J Lennert Veerman

ObjectiveTo assess the potential impact of reduction in salt intake on the burden of cardiovascular disease (CVD) and premature mortality in Cameroon.MethodsUsing a multicohort proportional multistate life table model with Markov process, we modelled the impact of WHO’s recommended 30% relative reduction in population-wide sodium intake on the CVD burden for Cameroonian adults alive in 2016. Deterministic and probabilistic sensitivity analyses were conducted and used to quantify uncertainty.ResultsOver the lifetime, incidence is predicted to decrease by 5.2% (95% uncertainty interval (UI) 4.6 to 5.7) for ischaemic heart disease (IHD), 6.6% (95% UI 5.9 to 7.4) for haemorrhagic strokes, 4.8% (95% UI 4.2 to 5.4) for ischaemic strokes and 12.9% (95% UI 12.4 to 13.5) for hypertensive heart disease (HHD). Mortality over the lifetime is projected to reduce by 5.1% (95% UI 4.5 to 5.6) for IHD, by 6.9% (95% UI 6.1 to 7.7) for haemorrhagic stroke, by 4.5% (95% UI 4.0 to 5.1) for ischaemic stroke and by 13.3% (95% UI 12.9 to 13.7) for HHD. About 776 400 (95% UI 712 600 to 841 200) health-adjusted life years could be gained, and life expectancy might increase by 0.23 years and 0.20 years for men and women, respectively. A projected 16.8% change (reduction) between 2016 and 2030 in probability of premature mortality due to CVD would occur if population salt reduction recommended by WHO is attained.ConclusionAchieving the 30% reduction in sodium intake recommended by WHO could considerably decrease the burden of CVD. Targeting blood pressure via decreasing population salt intake could translate in significant reductions in premature CVD mortality in Cameroon by 2030.


2020 ◽  
Vol 222 (7) ◽  
pp. 1138-1144 ◽  
Author(s):  
Sarah M Bartsch ◽  
Elizabeth A Mitgang ◽  
Gail Geller ◽  
Sarah N Cox ◽  
Kelly J O’Shea ◽  
...  

Abstract Background The protection that an influenza vaccine offers can vary significantly from person to person due to differences in immune systems, body types, and other factors. The question, then, is what is the value of efforts to reduce this variability such as making vaccines more personalized and tailored to individuals. Methods We developed a compartment model of the United States to simulate different influenza seasons and the impact of reducing the variability in responses to the influenza vaccine across the population. Results Going from a vaccine that varied in efficacy (0–30%) to one that had a uniform 30% efficacy for everyone averted 16.0–31.2 million cases, $1.9–$3.6 billion in direct medical costs, and $16.1–$42.7 billion in productivity losses. Going from 0–50% in efficacy to just 50% for everyone averted 27.7–38.6 million cases, $3.3–$4.6 billion in direct medical costs, and $28.8–$57.4 billion in productivity losses. Going from 0–70% to 70% averted 33.6–54.1 million cases, $4.0–$6.5 billion in direct medical costs, and $44.8–$64.7 billion in productivity losses. Conclusions This study quantifies for policy makers, funders, and vaccine developers and manufacturers the potential impact of efforts to reduce variability in the protection that influenza vaccines offer (eg, developing vaccines that are more personalized to different individual factors).


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