HONG KONG,
CHINA – Media OutReach – 30 March 2020 – To combat the spread of COVID-19, the Chinese government
imposed an unprecedented and controversial lockdown on Wuhan, a city of 11
million people, starting on the morning of January 23, and then in other Hubei
cities several days later. Under the order issued by the government, all public
transport, including buses, trains, flights and ferry services, were suspended.
Residents of Wuhan were also not allowed to leave the city without permission.
This lockdown, which is only being
relaxed two months on as the number of new infections in China has tailed off,
is being emulated by a growing number of governments from the U.K, Italy and
Spain to the Philippines as infections have spread across the globe, with over
360,000 people infected and over 16,000
dead.
A new study has further strengthened
the case that COVID-19 cases in China would have been significantly higher had
the government not enacted the historic lockdown on the city of Wuhan in the
early days of the outbreak.
Conducted by Yang Yang,
Assistant Professor of School of Hotel and Tourism Management at The Chinese
University of Hong Kong (CUHK) Business School in collaboration with Prof.
Hanming Fang at the University of Pennsylvania and Prof. Long Wang of
ShanghaiTech University, the study sought to quantify and isolate the effect of
restricting travel on the spread of the virus.
It estimated COVID-19 infections
would have been 64.8 percent higher in Chinese cities outside Hubei province,
and 52.6 percent higher in the other cities within Hubei but outside the
provincial capital and outbreak epicentre of Wuhan, if the government had not
acted to shut the city.
The results of the latest study has
lent further weight to previous findings that
the lockdown significantly delayed the spread of the virus across China.
Entitled Human Mobility Restrictions and the Spread of the Novel
Coronavirus (2019-nCov) in China, it
examined data from Baidu Migration, a travel map offered by the Chinese search
engine of the same name, which tracks the real-time location of every smart
phone using the company’s mapping app.
Controlling for the fact that the
virus itself would have reduced travel on its own, and the panic would have
increased travel, it found that the lockdown on Wuhan itself cut the outflow of
people from the city by 56.4 percent compared to if a quarantine had not been
in place. The lockdown also reduced the inflow of people into the city by 76.6
percent and movement within the city by 54.2 percent.
These results were then correlated
with COVID-19 infections figures released by the Chinese Center for Disease
Control and Prevention, also known as China CDC.
“We find, using simulations
with these estimates, that the lockdown of the city of Wuhan contributed
significantly to reducing the total infection cases outside of Wuhan, even with
the social distancing measures later imposed by other cities,” says Prof.
Yang.
A World Without a Wuhan Quarantine
This model was also extrapolated to
estimate the actual number of infection cases in Wuhan and elsewhere in Hubei.
If a lockdown had not been put in
place, the 347 cities in China outside Hubei would have recorded a total of
20,810 cases as of the end of February, compared to the actual number of
12,626. Similarly, for 16 cities within Hubei but outside of Wuhan, cases would
have reached 23,400 without the mandatory quarantine, instead of the actual
15,330.
It also found a persistent gap
between the estimated number of infection cases with the actual numbers in
Wuhan from the start of the outbreak. This gap widened over time, possibly as a
result of the overwhelmed health care system and peaked on January 26, with
the number of official cases constituting 80.03 percent of the estimated total,
before tailing off to settle at around 11.3 percent.
“We are thus able to conclude
that almost all infection cases in Wuhan were able to be treated over time as
the stress on the health system was relieved,” says Prof. Yang, adding
that the discrepancy may be explained because some of the infected may have
recovered on their own or died without reporting their situation during the
early stages.
If the mandatory quarantine had not
been put in place, the simulation also predicted that new infections would
still have peaked on their own — on February 2 in Hubei excluding Wuhan, 9 days
after the real-world lock down took place, and on February 3 elsewhere in
China. It also predicted that estimated new cases would gradually converge to
the real-world reported daily cases by February 22.
“This suggests that the social
distancing measures implemented elsewhere in China would have worked eventually
to contain the spread of the virus, even if the city of Wuhan was not locked
down,” Prof Yang says. “However, the initial onslaught on the medical
system in all cities in China would have been much more severe, and the total
number of infection cases elsewhere would have been significantly higher.”
Do Less Stringent Lockdowns Work?
Elsewhere in China, the study also
looked at the effectiveness of less severe lockdowns implemented to different
degrees in other cities, from establishing checkpoints in building entrances
and quarantine zones, shutdowns on public transport as well as limits on the
movement of people in and out as well as within cities.
“The results suggest that these
enhanced social distancing policies in destination cities were effective in
reducing the impact of population inflows from Wuhan and other source cities in
Hubei. This in turn implies that population inflows from the epicentre
contribute to the spread of infection only before the social distancing
measures were applied.
“It appears that after
implementing various control measures, cities adopting an extended lockdown can
flatten the upward trajectory of the virus,” Prof. Yang adds, noting that
the results of the study will have strong implications on other countries in
their fight against COVID-19.
Reference:
Fang, Hanming and Wang, Long and
Yang, Yang, Human Mobility Restrictions and the Spread of the Novel Coronavirus
(2019-nCoV) in China (March 23, 2020). PIER Working Paper No. 20-011. Available
at SSRN: https://ssrn.com/abstract=3559382 or http://dx.doi.org/10.2139/ssrn.3559382
This article was first published in the China
Business Knowledge (CBK) website by CUHK Business School: https://bit.ly/39mi7YJ.
About CUHK Business School
CUHK
Business School comprises two schools — Accountancy and Hotel and
Tourism Management — and four departments — Decision Sciences and
Managerial Economics, Finance, Management and Marketing. Established
in Hong Kong in 1963, it is the first business school to offer BBA, MBA and
Executive MBA programmes in the region. Today, the School
offers 8 undergraduate programmes and 20
graduate programmes including MBA, EMBA,
Master, MSc, MPhil and Ph.D.
In
the Financial Times Global MBA Ranking 2020,
CUHK MBA is ranked 50th. In FT‘s 2019 EMBA ranking, CUHK EMBA is ranked 24th
in the world. CUHK Business School has the largest number of business alumni (36,000+)
among universities/business schools in Hong Kong — many of whom are key
business leaders. The School currently has about 4,400
undergraduate and postgraduate students and Professor Lin Zhou
is the Dean of CUHK Business School.
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