The role of population mobility and non-pharmaceutical interventions on COVID-19 infection: A Canadian case study of Granger-Causal relationships


Background: The Coronavirus disease (COVID-19) has been the cause of more than 13,350 deaths in Canada. As a result, nonpharmaceutical interventions (NPIs) have been adopted by government officials to mitigate dissemination of the disease. Quantifying NPI effectiveness is challenging due to variability in their implementation between geographic regions. Mobility data can help understand the role of NPIs in reducing COVID-19 cases. Methods: The data used in this analysis consists of individual level time-series of confirmed positive COVID-19 cases in six Canadian provinces, population mobility trends and timing and level of NPI implementation. The Granger causality test was used to assess bi-directional predictive causality between NPIs, mobility and COVID-19 daily cases per 100 000 population. Findings: Using data from February 15th to December 28th 2020, we found that implementations of NPI and daily COVID-19 cases causally influence population mobility in all provinces. The relationship between daily cases and NPIs remains unclear. Conclusion: This study showed that in six Canadian provinces, NPIs and daily cases contributed to minimizing population mobility, but suggested that NPIs may have to be implemented and enforced more promptly to significantly influence the incidence of COVID-19 cases.

Preprint available at SSRN