scholarly journals Examining the Effects of the Sacramento Dockless E-Bike Share on Bicycling and Driving

2021 ◽  
Vol 13 (1) ◽  
pp. 368
Author(s):  
Dillon T. Fitch ◽  
Hossain Mohiuddin ◽  
Susan L. Handy
Keyword(s):  
Travel Behavior ◽  
Regression Models ◽  
Population Level ◽  
Panel Survey ◽  
Multilevel Regression ◽  
Combine Data ◽  
Cross Sectional ◽  
Individual Level ◽  
Before And After ◽  
Bike Share

One way cities are looking to promote bicycling is by providing publicly or privately operated bike-share services, which enable individuals to rent bicycles for one-way trips. Although many studies have examined the use of bike-share services, little is known about how these services influence individual-level travel behavior more generally. In this study, we examine the behavior of users and non-users of a dockless, electric-assisted bike-share service in the Sacramento region of California. This service, operated by Jump until suspended due to the coronavirus pandemic, was one of the largest of its kind in the U.S., and spanned three California cities: Sacramento, West Sacramento, and Davis. We combine data from a repeat cross-sectional before-and-after survey of residents and a longitudinal panel survey of bike-share users with the goal of examining how the service influenced individual-level bicycling and driving. Results from multilevel regression models suggest that the effect of bike-share on average bicycling and driving at the population level is likely small. However, our results indicate that people who have used-bike share are likely to have increased their bicycling because of bike-share.

Temporal Variability of Car Use as an Input to Design of Before and After Surveys

2003 ◽  
Vol 1855 (1) ◽  
pp. 112-120 ◽  
Author(s):  
A. J. Richardson
Keyword(s):  
Travel Behavior ◽  
Design Parameters ◽  
Panel Survey ◽  
Sample Sizes ◽  
Cross Sectional ◽  
Travel Diary ◽  
Before And After ◽  
Travel Diaries ◽  
Household Travel ◽  
Larger Sample

Before and after surveys are a common method for measuring the effect of specific policies and projects designed to cause changes in travel behavior. Design issues of before and after surveys used to evaluate projects designed to change travel behavior are addressed. A quantitative understanding of the underlying variability of the parameters to be measured was needed—in particular, the variation over time in car travel by individuals and households. Since no data were available locally, a detailed analysis was made of the 6-week travel diaries from the MobiDrive survey conducted in Germany to estimate the coefficients of variation in key travel parameters. These results were then adapted for use in the presented project. Several features emerged from this analysis. First, in general, larger sample sizes are needed to detect changes in either distance traveled or travel time than for trips undertaken. Second, larger sample sizes are needed to detect changes from repeated cross-sectional surveys than from a panel survey. Third, larger sample sizes are needed to detect changes when using a daily travel diary, compared with use of a weekly travel diary (although this difference can be substantially reduced in a panel survey by maintaining the same day of the week for each household in later waves of the panel). Finally, larger sample sizes are needed to detect changes from person travel data than from household travel data. However, some of the design parameters that allow smaller sample sizes also make the survey more difficult to conduct.

scholarly journals Online News and Protest Participation in a Political Context: Evidence from Self-Reported Cross-Sectional Data

2021 ◽  
Vol 7 (1) ◽  
pp. 205630512098445
Author(s):  
Nora Kirkizh ◽  
Olessia Koltsova
Keyword(s):  
Digital Media ◽  
Regression Models ◽  
Online News ◽  
Political Context ◽  
Government Control ◽  
Multilevel Regression ◽  
Traditional Media ◽  
Cross Sectional ◽  
Internet Media ◽  
The Relationship

Availability of alternative information through social media, in particular, and digital media, in general, is often said to induce social discontent, especially in states where traditional media are under government control. But does this relation really exist, and is it generalizable? This article explores the relationship between self-reported online news consumption and protest participation across 48 nations in 2010–2014. Based on multilevel regression models and simulations, the analysis provides evidence that those respondents who reported that they had attended a protest at least once read news online daily or weekly. The study also shows that the magnitude of the effect varies depending on the political context: surprisingly, despite supposedly unlimited control of offline and online media, autocratic countries demonstrated higher effects of online news than transitional regimes, where the Internet media are relatively uninhibited.

scholarly journals Urine Spot Samples Can Be Used to Estimate 24-Hour Urinary Sodium Excretion in Children

2018 ◽  
Vol 148 (12) ◽  
pp. 1946-1953 ◽  
Author(s):  
Magali Rios-Leyvraz ◽  
Pascal Bovet ◽  
René Tabin ◽  
Bernard Genin ◽  
Michel Russo ◽  
...  
Keyword(s):  
Sodium Excretion ◽  
Salt Intake ◽  
Sodium Intake ◽  
Population Level ◽  
Urinary Sodium Excretion ◽  
Cross Sectional Study ◽  
Urinary Sodium ◽  
Cross Sectional ◽  
High Sodium ◽  
Individual Level

ABSTRACT Background The gold standard to assess salt intake is 24-h urine collections. Use of a urine spot sample can be a simpler alternative, especially when the goal is to assess sodium intake at the population level. Several equations to estimate 24-h urinary sodium excretion from urine spot samples have been tested in adults, but not in children. Objective The objective of this study was to assess the ability of several equations and urine spot samples to estimate 24-h urinary sodium excretion in children. Methods A cross-sectional study of children between 6 and 16 y of age was conducted. Each child collected one 24-h urine sample and 3 timed urine spot samples, i.e., evening (last void before going to bed), overnight (first void in the morning), and morning (second void in the morning). Eight equations (i.e., Kawasaki, Tanaka, Remer, Mage, Brown with and without potassium, Toft, and Meng) were used to estimate 24-h urinary sodium excretion. The estimates from the different spot samples and equations were compared with the measured excretion through the use of several statistics. Results Among the 101 children recruited, 86 had a complete 24-h urine collection and were included in the analysis (mean age: 10.5 y). The mean measured 24-h urinary sodium excretion was 2.5 g (range: 0.8–6.4 g). The different spot samples and equations provided highly heterogeneous estimates of the 24-h urinary sodium excretion. The overnight spot samples with the Tanaka and Brown equations provided the most accurate estimates (mean bias: −0.20 to −0.12 g; correlation: 0.48–0.53; precision: 69.7–76.5%; sensitivity: 76.9–81.6%; specificity: 66.7%; and misclassification: 23.0–27.7%). The other equations, irrespective of the timing of the spot, provided less accurate estimates. Conclusions Urine spot samples, with selected equations, might provide accurate estimates of the 24-h sodium excretion in children at a population level. At an individual level, they could be used to identify children with high sodium excretion. This study was registered at clinicaltrials.gov as NCT02900261.

scholarly journals Modeling Dynamic Heterogeneity Using Gaussian Processes

2019 ◽  
Vol 57 (1) ◽  
pp. 55-77 ◽  
Author(s):  
Ryan Dew ◽  
Asim Ansari ◽  
Yang Li
Keyword(s):  
Gaussian Processes ◽  
Marketing Research ◽  
Population Level ◽  
Online Reviews ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Dynamic Heterogeneity ◽  
Cross Sectional ◽  
Individual Level ◽  
The Rich

Marketing research relies on individual-level estimates to understand the rich heterogeneity of consumers, firms, and products. While much of the literature focuses on capturing static cross-sectional heterogeneity, little research has been done on modeling dynamic heterogeneity, or the heterogeneous evolution of individual-level model parameters. In this work, the authors propose a novel framework for capturing the dynamics of heterogeneity, using individual-level, latent, Bayesian nonparametric Gaussian processes. Similar to standard heterogeneity specifications, this Gaussian process dynamic heterogeneity (GPDH) specification models individual-level parameters as flexible variations around population-level trends, allowing for sharing of statistical information both across individuals and within individuals over time. This hierarchical structure provides precise individual-level insights regarding parameter dynamics. The authors show that GPDH nests existing heterogeneity specifications and that not flexibly capturing individual-level dynamics may result in biased parameter estimates. Substantively, they apply GPDH to understand preference dynamics and to model the evolution of online reviews. Across both applications, they find robust evidence of dynamic heterogeneity and illustrate GPDH’s rich managerial insights, with implications for targeting, pricing, and market structure analysis.

Food Insecurity Among Older Adults: A Multilevel Analysis of State-Level Interventions

2019 ◽  
pp. 073346481989423
Author(s):  
Pablo Gaitán-Rossi ◽  
Ida Caterina García-Appendini ◽  
Lucía Félix-Beltrán ◽  
Mireya Vilar-Compte
Keyword(s):  
Older Adults ◽  
Food Insecurity ◽  
Regression Models ◽  
State Level ◽  
Cross Sectional Study ◽  
Social Programs ◽  
Multilevel Regression ◽  
Cross Sectional ◽  
Monetary Transfers ◽  
Food Programs

Objective: To analyze whether state-level social programs for older adults (OAs) in Mexico are associated with a reduction: (a) in the prevalence of severe food insecurity (SFI) and (b) in the magnitude of the effect of municipal marginalization on SFI. Method: Cross-sectional study based on urban OAs (65–100 years) from the 2010 census. Three-level logistic multilevel regression models were estimated to explain SFI. Results: Controlling for individual and municipal characteristics, states with social programs for OAs are generally associated with lower SFI prevalences (odds ratio [OR] = 0.68 [0.48, 0.95]) and mitigate the effect of marginalization on SFI when compared with states with no programs. Compared with in-kind food programs and voucher-based programs, monetary transfers are associated with a significant reduction in SFI prevalence (OR = 0.68 [0.46, 0.99]). Conclusion: States with programs for OAs, mainly monetary transfers, are associated with lower SFI prevalences.

scholarly journals Changes in Occupational Tasks and Their Association with Individual Wages and Occupational Mobility

2019 ◽  
Vol 20 (4) ◽  
pp. e295-e328
Author(s):  
Alexandra Fedorets
Keyword(s):  
Large Scale ◽  
Occupational Mobility ◽  
Wage Growth ◽  
Panel Survey ◽  
Proximity Measure ◽  
Wage Dynamics ◽  
Cross Sectional ◽  
Individual Level ◽  
Occupational Tasks ◽  
Over Time

Abstract This study provides novel evidence on the relevance of task content changes between and within occupations to wage dynamics of occupational changers and stayers. I use individual-level, cross-sectional data featuring tasks performed on the job to compute a measure of proximity of job contents. Then, I merge this measure to a large-scale panel survey to show that occupational changers experience a wage growth that is declining when the accompanying alterations in task contents are big. For occupational stayers, alterations in task contents generate a positive wage component, beyond tenure effect. However, the results are not robust with respect to the choice of proximity measure and over time.

Self-employment and Civic Inclination

2020 ◽  
Vol 63 (5) ◽  
pp. 719-737
Author(s):  
F. Carson Mencken ◽  
Bethany Smith ◽  
Charles M. Tolbert
Keyword(s):  
Regression Models ◽  
Political Activism ◽  
The Self ◽  
Data Sets ◽  
County Level ◽  
Cross Sectional ◽  
Individual Level ◽  
Self Employment ◽  
Level Data ◽  
Building Community

We test whether the self-employed have higher levels of civic inclination (trust, political activism, community closeness, community participation) compared to workers from the private sector. We examine the civic inclinations of the self-employed with two national cross-sectional data sets. We use a variety of discrete and continuous regression models. We find that the self-employed have higher levels of political activism, feel closer to neighbors and family, and have greater odds of engaging to solve community problems. We fail to detect differences in donating money, attending community events, and closeness to friends. Previous research has concluded with county-level data that the self-employed are important actors in building community and creating social capital. Our results add to this literature by showing that the self-employed have higher levels of civic inclination with individual-level data. Implications for theory and research are discussed.

Developing Crash Modification Factors for Horizontal Curves on Rural Two-Lane Undivided Highways Using a Cross-Sectional Study

2017 ◽  
Vol 2636 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Lingtao Wu ◽  
Dominique Lord ◽  
Srinivas Reddy Geedipally
Keyword(s):  
Regression Models ◽  
Cross Sectional Study ◽  
Highway Safety ◽  
Sectional Study ◽  
Cross Sectional ◽  
Highway Safety Manual ◽  
Horizontal Curves ◽  
Before And After ◽  
Crash Modification Factors ◽  
Curve Radius

Horizontal curves have been identified as experiencing more crashes than tangent sections on roadways, especially on rural two-lane highways. The first edition of the Highway Safety Manual provides crash modification functions (CM functions) for curves on rural two-lane highways. The CM functions proposed in the manual may suffer from both outdated data and analysis technique. Before-and-after studies are usually the preferred method for estimating the safety effects of treatments. Unfortunately, this method is not feasible for curves. Previous studies have frequently used regression models for developing CM functions for horizontal curves. As recently documented in the literature, some potential problems exist with using regression models to develop crash modification factors. This research utilized a cross-sectional study to develop curvature CM functions. Curves located on Texas rural two-lane undivided highways were divided into a number of bins based on the curve radius. Safety was predicted with the assumption that these curves had been tangents. The observed number of crashes that occurred on the curves was compared with the dummy tangents and for different bins. The results showed that the horizontal curve radius has a significant role in the risk of a crash. From these results, a new CM function was developed. The prediction performance of the Highway Safety Manual CM function was compared with the new CM function in this study and another function that was recently proposed in the literature. It was found that the new CM function documented in this study outperformed both.

scholarly journals Meeting UK dietary recommendations is associated with higher estimated consumer food costs: an analysis using the National Diet and Nutrition Survey and consumer expenditure data, 2008–2012

2017 ◽  
Vol 21 (5) ◽  
pp. 948-956 ◽  
Author(s):  
Nicholas RV Jones ◽  
Tammy YN Tong ◽  
Pablo Monsivais
Keyword(s):  
Saturated Fat ◽  
Population Level ◽  
Cross Sectional Study ◽  
Primary Outcome Measure ◽  
Future Research ◽  
Consumer Expenditure ◽  
Dietary Recommendations ◽  
Nutrition Survey ◽  
Cross Sectional ◽  
Individual Level

AbstractObjectiveTo test whether diets achieving recommendations from the UK’s Scientific Advisory Committee on Nutrition (SACN) were associated with higher monetary costs in a nationally representative sample of UK adults.DesignA cross-sectional study linking 4 d diet diaries in the National Diet and Nutrition Survey (NDNS) to contemporaneous food price data from a market research firm. The monetary cost of diets was assessed in relation to whether or not they met eight food- and nutrient-based recommendations from SACN. Regression models adjusted for potential confounding factors. The primary outcome measure was individual dietary cost per day and per 2000 kcal (8368 kJ).SettingUK.SubjectsAdults (n 2045) sampled between 2008 and 2012 in the NDNS.ResultsOn an isoenergetic basis, diets that met the recommendations for fruit and vegetables, oily fish, non-milk extrinsic sugars, fat, saturated fat and salt were estimated to be between 3 and 17 % more expensive. Diets meeting the recommendation for red and processed meats were 4 % less expensive, while meeting the recommendation for fibre was cost-neutral. Meeting multiple targets was also associated with higher costs; on average, diets meeting six or more SACN recommendations were estimated to be 29 % more costly than isoenergetic diets that met no recommendations.ConclusionsFood costs may be a population-level barrier limiting the adoption of dietary recommendations in the UK. Future research should focus on identifying systems- and individual-level strategies to enable consumers achieve dietary recommendations without increasing food costs. Such strategies may improve the uptake of healthy eating in the population.

scholarly journals Evaluation of multi-assay algorithms for identifying individuals with recent HIV infection: HPTN 071 (PopART)

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0258644
Author(s):  
Wendy Grant-McAuley ◽  
Ethan Klock ◽  
Oliver Laeyendecker ◽  
Estelle Piwowar-Manning ◽  
Ethan Wilson ◽  
...  
Keyword(s):  
Viral Suppression ◽  
Point Of Care ◽  
Population Level ◽  
Hiv Viral Load ◽  
Cross Sectional ◽  
Individual Level ◽  
Viral Loads ◽  
Incidence Estimation ◽  
Duration Of Infection ◽  
Recent Hiv Infection

Background Assays and multi-assay algorithms (MAAs) have been developed for population-level cross-sectional HIV incidence estimation. These algorithms use a combination of serologic and/or non-serologic biomarkers to assess the duration of infection. We evaluated the performance of four MAAs for individual-level recency assessments. Methods Samples were obtained from 220 seroconverters (infected <1 year) and 4,396 non-seroconverters (infected >1 year) enrolled in an HIV prevention trial (HPTN 071 [PopART]); 28.6% of the seroconverters and 73.4% of the non-seroconverters had HIV viral loads ≤400 copies/mL. Samples were tested with two laboratory-based assays (LAg-Avidity, JHU BioRad-Avidity) and a point-of-care assay (rapid LAg). The four MAAs included different combinations of these assays and HIV viral load. Seroconverters on antiretroviral treatment (ART) were identified using a qualitative multi-drug assay. Results The MAAs identified between 54 and 100 (25% to 46%) of the seroconverters as recently-infected. The false recent rate of the MAAs for infections >2 years duration ranged from 0.2%-1.3%. The MAAs classified different overlapping groups of individuals as recent vs. non-recent. Only 32 (15%) of the 220 seroconverters were classified as recent by all four MAAs. Viral suppression impacted the performance of the two LAg-based assays. LAg-Avidity assay values were also lower for seroconverters who were virally suppressed on ART compared to those with natural viral suppression. Conclusions The four MAAs evaluated varied in sensitivity and specificity for identifying persons infected <1 year as recently infected and classified different groups of seroconverters as recently infected. Sensitivity was low for all four MAAs. These performance issues should be considered if these methods are used for individual-level recency assessments.

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