People inflows as a pandemic trigger: Evidence from a quasi-experimental study

Area of Science:

• Epidemiology
• Public Health
• Economics

Background:

• Population density is a known factor in COVID-19 transmission.
• The causal role of economic activities, and associated mobility changes, in pandemic spread remains under-examined.

Purpose of the Study:

• To investigate the causal relationship between economic activities (tourism) and COVID-19 pandemic development.
• To analyze the impact of mobility changes driven by tourism on virus emergence in Sardinia.

Main Methods:

• Utilized a difference-in-differences approach.
• Examined tourism inflows as a proxy for economic activity and mobility changes.
• Analyzed COVID-19 case data in Sardinia during 2020.

Main Results:

• Identified a strong causal relationship between tourism flows and COVID-19 case emergence.
• Estimated a 4.1% elasticity of COVID-19 cases with respect to tourist share.
• Observed a higher elasticity of 5.1% when excluding local residents, indicating a significant impact of external mobility.

Conclusions:

• Economic activities, particularly tourism, can trigger widespread COVID-19 transmission in previously uninfected locations.
• Changes in population density due to economic factors are critical drivers of pandemic spread.
• Findings provide evidence for risk-prevention policies related to mobility and economic activities during pandemics.