Since the outbreak of the Covid-19 pandemic economists have turned to the SIR model and its subsequent variants for the study of the pandemic's economic impact. But the SIR model is lacking the optimising behaviour of economic models, in which agents can influence future transitions with their present actions. We borrow ideas and modelling techniques from the Mortensen-Pissarides (1994) search and matching model and show that there is a well-defined solution in line with the original claims of Kermack and McKendrick (1927) but in which incentives play a role in determining the transitions. There are also externalities that justify government intervention in the form of imposing more restrictions on actions outside the home than a decentralised equilibrium would yield.

Citation

Moen, E, C Pissarides and P Garibaldi (2020), ‘Modelling Contacts and Transitions in the SIR Epidemics Model‘, COVID Economics 5, CEPR Press, Paris & London. https://cepr.org/publications/covid-economics-issue-5#392514_392881_390356

In this paper we argue that endogenous shifts in private consumption behaviour across sectors of the economy can act as a potent mitigation mechanism during an epidemic or when the economy is re-opened after a temporary lockdown. Extending the theoretical framework proposed by Eichenbaum-Rebelo-Trabandt (2020), we distinguish goods by the degree to which they can be consumed at home rather than in a social (and thus possibly contagious) context. We demonstrate that, within the model the Swedish solution" of letting the epidemic play out without government intervention and allowing agents to shift their sectoral behavior on their own can lead to a substantial mitigation of the economic and human costs of the Covid-19 crisis

Citation

Uhlig, H, T Xie and D Krueger (2020), ‘Macroeconomic Dynamics and Reallocation in an Epidemic‘, COVID Economics 5, CEPR Press, Paris & London. https://cepr.org/publications/covid-economics-issue-5#392514_392881_391016

We provide perspective on the possible global economic and financial effects from COVID-19 by examining the handful of similar major health crises in the 21st century. We estimate the effects of these disease shock episodes on GDP growth, fiscal policy, expectations, financial markets, and corporate activity. Simple time-series models of GDP growth indicate that real GDP is 2.6% lower on average across 210 countries in the year of the official declaration of the outbreak and is still 3% below its pre-shock level five years later. The negative effect on GDP is felt less in countries with more aggressive first-year responses in government spending. Consensus forecast data suggests a pessimistic view on real GDP initially that lasts for two months, an effect that is larger for emerging market economies. Stock market responses indicate an immediate negative reaction. Finally, using firm-level data, we find a fall in corporate profitability and employment, and an increase in debt, the last of which is further reflected in higher sovereign CDS spreads.

Citation

Rogers, J, S Zhou and C Ma (2020), ‘Global Economic and Financial Effects of 21st Century Pandemics and Epidemics‘, COVID Economics 5, CEPR Press, Paris & London. https://cepr.org/publications/covid-economics-issue-5#392514_392881_390357

As an alternative to structural estimates of the SIR model, this note presents reduced-form time series forecasts of the growth in Covid-19 cases s and fatalities d for several countries where a slowdown has set in. Once a daily threshold of d >100 was crossed, daily growth in the initial unchecked phase was around ?ln(d) ? [0.2,0.3]. For several countries, growth in fatalities as well as registered cases now shows a sustained decline; Italy and Spain report ?ln(d) ? 0.03. I present updated ETS forecasts of the endpoint to the current epidemic for the countries in the sample, along with predicted fatalities. As a robustness check, forecasts from 31 March alongside later realizations are included. Results are preliminary and subject to daily revision as the situation is still evolving rapidly. The relative success of the method suggests univariate forecasts as a quick way of assessing resource needs and timelines where the epidemic is still ongoing.

Citation

Ritschl, A (2020), ‘Visualizing and Forecasting Covid-19‘, COVID Economics 5, CEPR Press, Paris & London. https://cepr.org/publications/covid-economics-issue-5#392514_392881_390358

We conducted a repeated survey on risk taking behavior across a panel of subjects in Wuhan, China – ground zero of the Coronavirus pandemic – before and after the outbreak began. Our baseline survey was administered on October 16th, 2019 among graduate students in Wuhan prior to the COVID-19 outbreak. 47% of the students in our sample returned home to other provinces in China for semester break in early January before the province of Hubei and the city of Wuhan was locked down with strict quarantine orders on 23 January 2020. We administered a follow up survey to the same subjects, capturing their geolocation information on 28 February. We use variation in exposure across different Chinese cities and provinces to measure the impact of the Coronavirus pandemic on subjects’ willingness to take risk. We find that subjects’ allocations of wealth to hypothetical risky investments decrease monotonically based on the strength of their exposure to the pandemic. However, subjects uniformly report substantially lower general preferences for risk regardless of their exposure. Higher levels of exposure leads subjects to reduce beliefs in their own luck and sense of control and in turn, form more pessimistic beliefs on the economy and social conditions. We provide evidence that short-term changes in risk taking may stem more so from changes in beliefs and optimism than from general risk preferences. Our results suggest that more closely held formative experiences have large, negative, and acute effects on economic preferences during a crisis.

We conducted a repeated survey on risk taking behavior across a panel of subjects in Wuhan, China – ground zero of the Coronavirus pandemic – before and after the outbreak began. Our baseline survey was administered on October 16th, 2019 among graduate students in Wuhan prior to the COVID-19 outbreak. 47% of the students in our sample returned home to other provinces in China for semester break in early January before the province of Hubei and the city of Wuhan was locked down with strict quarantine orders on 23 January 2020. We administered a follow up survey to the same subjects, capturing their geolocation information on 28 February. We use variation in exposure across different Chinese cities and provinces to measure the impact of the Coronavirus pandemic on subjects’ willingness to take risk. We find that subjects’ allocations of wealth to hypothetical risky investments decrease monotonically based on the strength of their exposure to the pandemic. However, subjects uniformly report substantially lower general preferences for risk regardless of their exposure. Higher levels of exposure leads subjects to reduce beliefs in their own luck and sense of control and in turn, form more pessimistic beliefs on the economy and social conditions. We provide evidence that short-term changes in risk taking may stem more so from changes in beliefs and optimism than from general risk preferences. Our results suggest that more closely held formative experiences have large, negative, and acute effects on economic preferences during a crisis.

Citation

Liu, Y, T Hanspal, Y Liao and D Bu (2020), ‘Risk Taking during a Global Crisis: Evidence from Wuhan‘, COVID Economics 5, CEPR Press, Paris & London. https://cepr.org/publications/covid-economics-issue-5#392514_392881_390359

We recommend the immediate universal adoption of cloth facemasks, including homemade masks, and accompanying policies to increase the supply of medical masks for health workers. Universal adoption will likely slow the spread of the Covid-19 virus by reducing transmission from asymptomatic individuals. We provide strongly suggestive evidence from cross-country data that facemask use slows the growth rate of cases and deaths. This complements extant scientific data on mask usage. Our analysis suggests each cloth facemask generates thousands of dollars in value from reduced mortality risk. Each medical mask, when used by a healthcare worker, may generate millions of dollars in value, and policies to encourage greater production prioritised for health workers are urgently needed.

Citation

Ko, A, E Kaplan, H Forman, N Christakis, J Chevalier and J Abaluck (2020), ‘The Case for Universal Cloth Mask Adoption & Policies to Increase the Supply of Medical Masks for Health Workers‘, COVID Economics 5, CEPR Press, Paris & London. https://cepr.org/publications/covid-economics-issue-5#392514_392881_390360