Estimation of the economic effect of a lockdown of Tokyo against COVID-19, including the propagation effect on other regions through supply chains. A illustrative summary of a paper available at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3564898

1. The propagation of the economic impact
through supply chains:
The case of a mega-city lockdown
against the spread of COVID-19
Hiroyasu Inoue
University of Hyogo
Yasuyuki Todo
Waseda University
March 31, 2020

2. Outside
Tokyo
In Tokyo
Summary
• The economic effect of a lockdown of Tokyo propagates to
other regions through supply chains, resulting in a huge
production loss in Japan.
• A lockdown for a month would reduce production in Tokyo
by 9 trillion yen and outside Tokyo by 18 trillion yen. The
total production loss would be 27 trillion yen (5% of GDP).

3. 1. Order 2. Demand
4. Production3. Inventory renewal
3
Method
Based on Inoue and Todo (2019),
Nature Sustainability,
we apply an agent-based
model of supply chains
to the actual data of 1 million
firms in Japan
and simulate the effect of a lockdown.
Created by Yuzuka Kashiwagi
(Waseda University)

4. Assumptions in the simulation
• All non-essential production activities in
the center of Tokyo are shut down.
– Essential activities: wholesale, retail, utility,
transport, healthcare, communication
lock-
down
• The effect of a lockdown propagates to
other regions through supply chains.
– No supply of parts from Tokyo
affect downstream sectors outside Tokyo
– No demand of Tokyo for parts
affect upstream sectors outside Tokyo
Propagation

5. Main Results
Duration of
lockdown
Production
loss in
Tokyo
Production
loss outside
Tokyo
Total loss
% of
GDP
(trillion yen)
1 day 0.309 252 561 0.11
1 week 2.2 1.6 3.7 0.72
2 weeks 4.3 5.0 9.3 1.76
1 month 9.3 18.5 27.8 5.25
2 months 18.6 50.0 68.2 12.9
Highlights
• Huge effect
• When the lockdown in long, the loss outside Tokyo is larger
than the loss in Tokyo.
• Doubling the lockdown duration more than doubles the loss.

6. Main Results
Day 1
Day 14
●Company that
reduces production
by more than 80%
Highlight
• The effect spreads across Japan day by day.

7. Main Results
After a month, daily
production in Japan
would be 1/7 of that
before COVID-19.

8. Policy Implications
• A lockdown of a mega city would affect other
regions, leading to a substantial economic loss.
Therefore, it is suggested to employ all possible
measures to avoid any lockdown.
– Public support to invest in social-distancing environments
in workplaces (online working, reorganization of
production lines, …)
– Compensation to shut down sectors in which social
distancing is difficult (restaurants, pubs, concert halls, …)
• If a lockdown is unavoidable, it should be as short
as possible. (Doubling the lockdown duration more than
doubles the loss.)

9. Inoue, Hiroyasu and Todo, Yasuyuki (2020), The propagation of
the economic impact through supply chains: The case of a
mega-city lockdown against the spread of COVID-19. SSRN.
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3564898
Hiroyasu Inoue
• Associate professor, Graduate School of Simulation Studies,
University of Hyogo
• Ph.D. in informatics (Kyoto University)
• inoue@sim.u-hyogo.ac.jp
Yasuyuki Todo
• Professor, Graduate School of Economics, Waseda University
• Ph.D. in economics (Stanford University)
• yastodo@waseda.jp
Introduction of the paper and authors