Computing Mobility

The Twitter Social Mobility Index is a measure of social distancing and travel derived from Twitter data. We use public geolocated Twitter data to measure how much a user travels in a given week. We compute the standard deviation of Twitter geolocated tweets per week, and aggregate the data over an entire population to produce a metric for the US as a whole and for individual states and cities.

You can find a complete description of our method and results in our paper.

Results

The highlights of our study find that:

  • Since the start of social distancing on March 16, 2020 mobility in the United States has dropped 48.77%.

  • Every US state and territory has reduced mobility, though the variance by state is high.

  • States that were early adopters of social distancing practices have larger reductions in travel. The eight states that do not currently (April 5, 2020) have state wide orders rank lower: Arkansas (37), Iowa (50), Nebraska (29), North Dakota (13), South Carolina (34), South Dakota (39), Oklahoma (52), Utah (17),

  • The last two weeks of March have the lowest mobility of any week since January 1, 2019.

Mobility Reduction by State

This table shows the Twitter Social Mobility Index measured in kilometers for every state and territory in United States, New York City, and United States as a whole.

´╗┐Location Mobility from January 1, 2019 to March 15, 2020 Mobility in March 16 - March 29, 2020 Mobility Reduction Rank
AK 84.75 31.49 62.84% 2
AL 37.46 23.63 36.93% 47
AR 39.19 22.34 43.00% 37
AZ 47.30 25.37 46.37% 32
CA 59.47 28.64 51.84% 18
CO 54.21 23.82 56.05% 9
CT 34.16 15.35 55.05% 11
DC 58.45 21.55 63.13% 1
DE 33.38 17.39 47.90% 28
FL 59.29 34.61 41.62% 40
GA 51.43 29.46 42.73% 38
HI 112.71 70.14 37.77% 46
IA 38.23 24.49 35.94% 50
ID 53.61 34.07 36.44% 49
IL 41.95 18.97 54.79% 12
IN 34.69 19.30 44.35% 35
KS 50.44 23.67 53.07% 15
KY 33.99 16.48 51.51% 20
LA 36.53 21.65 40.74% 43
MA 43.50 18.59 57.27% 7
MD 34.94 14.81 57.61% 5
ME 46.42 27.19 41.42% 42
MI 42.79 22.12 48.31% 26
MN 47.75 23.23 51.35% 21
MO 39.89 20.49 48.64% 24
MS 39.63 25.59 35.42% 51
MT 52.46 32.23 38.56% 45
NC 39.89 20.32 49.06% 23
ND 48.94 22.50 54.02% 13
NE 40.66 21.26 47.73% 29
NH 41.97 21.66 48.38% 25
NJ 37.23 15.54 58.28% 4
NM 44.87 25.54 43.08% 36
NV 62.72 34.33 45.26% 33
NY 53.32 25.73 51.75% 19
OH 34.22 16.70 51.19% 22
OK 40.44 27.96 30.87% 52
OR 53.96 24.10 55.34% 10
PA 42.14 19.54 53.62% 14
PR 35.30 20.63 41.55% 41
RI 34.36 14.69 57.24% 8
SC 36.78 20.16 45.18% 34
SD 49.80 28.82 42.12% 39
TN 42.64 22.42 47.42% 30
TX 56.00 29.09 48.05% 27
UT 50.62 24.29 52.01% 17
VA 44.22 20.83 52.89% 16
VI 100.91 63.86 36.72% 48
VT 41.19 17.51 57.48% 6
WA 55.74 22.99 58.76% 3
WI 42.78 22.83 46.63% 31
WV 36.25 22.18 38.82% 44
WY 53.10 41.66 21.54% 53
United States 49.81 25.52 48.77% -
New York City 63.98 31.25 51.16% -

Here is a visualization of the table.

This figure shows the weekly social mobility index for Washington, DC (1), Wycoming (53) and the United States since January 6, 2020.