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. 2021 Apr 25;35:100840. doi: 10.1016/j.eclinm.2021.100840

Table 1.

Descriptive statistics of variables in the analysis of mobility ratio over the COVID-19 Course (March 8th to August 7th): US county level analysis.

All counties Analytic sample Hotspot sample
Dependent variable
 Mobility ratio 0.67 0.61
Baseline mobility 10.55 10.02
Black-White Dissimilarity index 0.46 0.46
State policy
 Stay-at-homea 0.28 0.26 0.30
 Reopenb 0.60 0.61 0.58
Geographic
 Metropolitan 0.37 0.49 0.55
 Northeast 0.07 0.09 0.28
 Midwest 0.34 0.24 0.16
 South 0.45 0.57 0.45
 West 0.14 0.11 0.10
Demographic
 Prop. Blackc 0.09 0.12 0.20
 Prop. Hispanicd 0.10 0.10 0.16
 Prop. Asiane 0.01 0.02 0.03
Pop. Density (in 1000)f 0.11 0.13 0.53
SES
 Vulnerability indexg 0.55 0.57 0.59
 Unemployment (1-month lagged)h 8.28 8.69 9.53
No. counties 3142 1972 135
No. county-days 480,573 283,097 19,256

Notes:

a

the proportion of days under stay-at-home order.

b

the proportion of days under reopening policy.

c

Proportion of the county population that identifies as Black in census records.

d

Proportion of the county population that identifies as Hispanic in census records.

e

Proportion of the county population that identifies as Asian in census records.

f

Population in thousands per square kilometers in 2018.

g

this is a composite measure for individuals below poverty, unemployed, with lower income, and with no high school diploma.

h

one-month lagged, time-varying monthly unemployment rates at the county level

Black-White Dissimilarity index is a measure of the evenness within counties Black and White residents are distributed across Census tracts. The index is only available for counties with a population having at least 100 Black people.

Mobility ratio is the median daily travel distance normalized by a baseline in order to capture the change of mobility levels over the pandemic course. It is calculated as the ratio of daily M50 from March 8 to August 7 relative to the baseline, the average of daily M50 between March 1 and March 7, obtained from mobile device locations by Descartes Labs.

Data: Hopkins Population Center COVID-19 Data Hub.