The EconomistMarch 28th 2020 191H
aving been quarantined at his par-
ents’ house in the Hebei province in
northern China for a month, Elvis Liu ar-
rived back home in Hong Kong on February
23rd. Border officials told him to add their
office’s number to his WhatsApp contacts
and to fix the app’s location-sharing setting
to “always on”, which would let them see
where his phone was at all times. They then
told him to get home within two hours,
close the door and stay there for two weeks.
His next fortnight was punctuated, ev-
ery eight hours, with the need to reactivate
that always-on location sharing; Facebook,
which owns WhatsApp, requires such affir-
mation so people do not just default to be-
ing tracked. Compared with his first lock-
down—in a spacious apartment, with
family and dogs for company—the ten-
square-metre flat with two tiny courtyard-
facing windows was grim. When he
emerged, on March 8th, he immediately
donned mask, goggles and gloves and tooka ferry to the island of Lamma where he gal-
loped down lush forest trails for 30km,
high on freedom, injuring his knees in the
process. He still has trouble sleeping. But
he is fit to work, and Hong Kong is content
that he poses no risk to the health of his fel-
low citizens.
Mainland China and South Korea have
reduced the number of reported new co-
vid-19 cases down to around 100 a day or
less; Hong Kong, Singapore and Taiwan
never saw steep rises in the first place (see
chart 1 on next page). Now they all face the
same challenge: how to limit the all-but-
inevitable rise in cases that will follow
when they relax current controls, a rise
which can already be seen in some places.
To meet that challenge they are all turningto information technology.
Their efforts, like others elsewhere, are
experimental. They risk failure; they also
risk adverse side-effects, most obviously
on civil liberties. But around 2.5bn people
have now been put on some sort of lock-
down during the pandemic (see chart 2 on
next page). Only a fraction of them have
been or will be infected, and thus become
immune. The rest, when they emerge, will
need watching—for their own sakes, and
for the sakes of those around them.
The tools in use fall into three catego-
ries. The first is documentation: using
technology to say where people are, where
they have been or what their disease status
is. The second is modelling: gathering data
which help explain how the disease
spreads. The third is contact tracing: iden-
tifying people who have had contact with
others known to be infected.
When it comes to documentation, most
of the action is in quarantine: replacing
phone calls and home visits with virtual
checking-up. While Hong Kong uses
WhatsApp, South Korea has a customised
app that sounds an alarm and alerts offi-
cials if people stray; as of March 21st 42% of
the 10,600 people under quarantine there
were using the app. Taiwan uses a different
approach, tracking quarantined people’s
phones using data from cell-phone masts.
If it detects someone out of bounds, it textsCreating the coronopticon
HONG KONG, SINGAPORE, SAN FRANCISCO, SEOUL AND TAIPEI
Surveillance through apps and data networks can do much to keep covid-19 at
bay, but at what cost?Briefing
22 Economic policy and covid-The pandemic and the state
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