Economics affects mobility, and ideology affects mask-wearing: How COVID-19 drifted to the red areas within the USA in 2020

The US experienced multiple, sustained outbreaks of COVID-19 in 2020. From March to November, the spread of the disease in the US showed puzzling patterns: the epicenter of the outbreak drifted from large urban Democractic centers to sparsely populated Republican and rural areas. Denser regions that were initially badly hit did comparatively better. This paper explains such a paradoxical diffusion of COVID-19 across US states and counties by pinning it down to the failure of two typical measures: social distancing and mask wearing. We build a behavioral model incorporating extrinsic incentives and intrinsic motivations to analyze the determinants of these two behaviors. We hypothesize that economic vulnerability (e.g., the risk that a country or an individual could be damaged by repeated financial shocks and instabilities), should be the key predictors of failure of social distancing. On the other hand, given the low cost of mask wearing, Conservatism and Trump-support should instead be the dominant predictors of this measure. We use county-level and state-level data to test these hypotheses. Using Standardized Seemingly Unrelated Regression and coefficient tests, we show that economic vulnerability largely predicts mobility, and ideology largely predicts mask wearing and does less for mobility. Also, we analyze the effect of these factors over time and find that for many indicators, Conservatism and Trump-support had a larger effect after August. This finding is strengthened by an increasing trend of correlation coefficients between Trump vote share and total cases per capita. These results, together, suggest that states and counties with lower economic vulnerability and Conservatism were likely to have better responses to COVID-19, and the effect of the latter was increasing in Fall, 2020.