Assessing the Spatial-Temporal Causal Impact of COVID-19 Related Policies on Epidemic Spread

Analyzing the causal impact of various government-related policies on the epidemic spread is of critical importance. This paper aims to investigate the problem of assessing the causal effects of different COVID-19 related policies on the USA epidemic spread in different counties at any given time period, while eliminating biased interference from unobserved confounders (e.g., the vigilance of residents). However, the infection outcome of each region is influenced not only by its own confounding factors but also by policy interventions implemented in neighboring regions. Furthermore, the government policy index may exhibit a time-delay influence on outbreak dynamics. To this end, we implement observational data about different COVID-19 related policies (treatment) and outbreak dynamics (outcome) across different U.S. counties over time, and develop a causal framework that learns the representations of time-varying confounders to tackle the aforementioned issues. More specifically, we employ one recurrent structure to capture the accumulative effects stemming from the policy history and then utilize hypergraph neural network to model the interactions among spatial regions. Our experimental results demonstrate the effectiveness of the proposed framework in quantifying the causal impact of different policy types on epidemics. Compared with baseline methods, our assessment provides valuable insights for future policy-making endeavors.