Economic Irreversibility in Pandemic Control Processes: Rigorous Modeling of Delayed Countermeasures and Consequential Cost Increases

Tsuyoshi Hondou

doi:10.7566/jpsj.90.114007

Abstract

After the first lockdown in response to the COVID-19 outbreak, many countries faced difficulties in balancing infection control with economics. Due to limited prior knowledge, economists began researching this issue using cost-benefit analysis and found that infection control processes significantly affect economic efficiency. A UK study used economic parameters to numerically demonstrate an optimal balance in the process, including keeping the infected population stationary. However, universally applicable knowledge, which is indispensable for the guiding principles of infection control, has not yet been clearly developed because of the methodological limitations of simulation studies. Here, we propose a simple model and theoretically prove the universal result of economic irreversibility by applying the idea of thermodynamics to pandemic control. This means that delaying infection control measures is more expensive than implementing infection control measures early while keeping infected populations stationary. This implies that once the infected population increases, society cannot return to its previous state without extra expenditures. This universal result is analytically obtained by focusing on the infection-spreading phase of pandemics, and is applicable not just to COVID-19, regardless of "herd immunity." It also confirms the numerical observation of stationary infected populations in its optimally efficient process. Our findings suggest that economic irreversibility is a guiding principle for balancing infection control with economic effects.

Highlights

Governments in several countries fear adverse economic effects and have hesitated to take measures to control the COVID-19 infection because the economic effects may result in illness and death in the non-infected population [1]
We demonstrate that delaying infection control measures is more expensive than implementing early measures while keeping the infected population stationary
Let us start the analyses of pandemic control processes

Summary

INTRODUCTION

Governments in several countries fear adverse economic effects and have hesitated to take measures to control the COVID-19 infection because the economic effects may result in illness and death in the non-infected population [1]. The optimal process includes the stationary state of the constant infected population in its principal part These results were obtained using numerical simulation because Rowthorn [1] assumed that an explicit solution was unavailable for this issue. It excludes more realistic effects that may modify its results, such as the effects of special inhomogeneity of infection distribution and influx of infected persons from outside the targeted area, the simple model clearly shows the fundamental property commonly underlying diverse pandemic control processes. For this purpose, we restrict ourselves to the infection-spreading phase in the pandemic model, in which the infected population grows exponentially in the absence of infection control. We will discuss the robustness of the result in the final section

Methods

Results

DISCUSSION and CONCLUSION