The Economist - USA (2020-11-28)

Sources:Covid19-projections.com;Google;Teralytics;BlavatnikSchoolofGovernment;SwapnilMishraetal.,ImperialCollegeLondon;SamAbbott

etal.,LSHTM*Baseline=medianmobilitybydayofweek,Jan3rd-Feb6th†Weightedbypopulation‡Baseline=medianmobilitybyday ofweek,Feb

Europe,impactofnationallockdownsonmobility,bylocation

11 countrieswithlockdownsinspringandautumn2020,as%ofusuallevel*

Europe,impactofnationallockdownsontheviralspreadrate(R)

Ninecountrieswithlockdownsinspringandautumn 2020

Changesinviralspreadrate(R)causedbyshiftsinmobility

FromautumnallockdownsinEnglandandWales, 2020

→Europe’slockdownshavehadlesseffectonmobilityinautumnthaninspring,buthavestillreducedtherateofnewinfections

100

11-country

average†

11-country

average†

0

20

40

60

80

-4 -2 0 2 4

Bars,restaurantsandshopping

-4 -2 0 2 4

Publictransport

-4 -2 0 2 4

Placesofwork

0

20

40

60

80

100

-4 -2 0 2 4

Supermarketsandpharmacies

Springlockdowns Autumnlockdowns

Weekoflockdown Weekoflockdown

0.5

1.0

1.5

2.0

2.5

3.0

-4 -3 -2 -1 0 1 2 3 4

9-country

average†

9-country

average†

Springlockdowns

Autumnlockdowns

↑Morenew

infections

Weekoflockdown

Lockdown

LockdownLockdown

Totaleffect

Tripsto

otherareas‡

Bars,restaurants

andshopping*

Placesofwork*

Supermarkets

andpharmacies*

95%confidence

-0.15 -0.10 -0.05 0 0.05

TheEconomistNovember 28th 2020 81

L

ess thana year after covid-19 spread

across the world, scientists have pro-

duced several vaccines that may offer high

immunity. But mass inoculation is months

away. Until then people must contain the

virus by wearing masks, travelling less and

limiting contact with other households.

Politicians who thought their citizens

would stop socialising of their own accord

have been disappointed. America’s daily

deaths are near record highs as the virus

runs amok. Europe’s cases surged in Octo-

ber, causing 11 governments to reimpose

national stay-at-home orders. They hope

these lockdowns will reduce infections to

manageable levels for Christmas. But after

a grim spring, they must worry that people

will be less compliant this time around.

Google’s smartphone data confirm that

Europe’s latest restrictions have had less

impact on daily life. In March the average

number of trips—to places such as super-

markets, restaurants, transport hubs and

offices—fell to 35% of the level in January.

After rebounding to 83% by the time of the

latest lockdowns, mobility has now

dropped only to 68%. This smaller effect

could be caused both by more flexible rules

and less enthusiasm for obeying them.

Yet these less stringent lockdowns are

still working. The London School of Hy-

giene and Tropical Medicine’s estimates of

r—the average number of new people who

catch the virus from each infected per-

son—are dropping. In European countries

that enacted second lockdowns, rfell from

an average of 1.1 in the week before the new

restrictions to 0.9 in the week after. That

small change makes a big difference. Over

four weeks, it would mean new infections

falling by 21%, rather than rising by 36%.

For 334 local authorities in England and

Wales (akin to America’s counties), we

have also calculated which aspects of lock-

downs matter most. We combined esti-

mates of rfrom Imperial College London

with travel records from Teralytics, a Swiss

technology firm, and Google’s smartphone

data. Then we used mediation analysis, a

statistical technique, to disentangle the ef-

fects of different types of mobility.

We found two ways that lockdowns

suppress r. First, reducing trips to work

helps, as do fewer outings to restaurants,

bars and shops, though the effect of those

leisure settings may vary a lot. (Usage of

parks or public transport had no impact,

perhaps because visitors are outside or

wearing masks.) Second, lockdowns deter

people from travelling to other local au-

thorities. This is probably the most impor-

tant factor in decreasing roverall.

This is all good news. Looser lockdowns

cost less than total closures. And when

governments reopen businesses, they can

mitigate extra mingling among customers

by urging them to stay in their local areas,

for now. That is the best way to get the virus

under control before Christmas. 7

Europe’s new stay-at-home orders are

slowing transmission of the virus

Second act

Graphic detailCovid-19 and lockdowns