We exploit threshold rules governing margin trading eligibility in India to identify a causal link between margin trading and increased comovement during crises. Margin trading explains more than one quarter of the increase return comovement that we observe during crises. To understand the...

We collect a time-series database of business and related restrictions for every county in the United States from March through December 2020. We find strong and consistent evidence that employee mask policies, mask mandates for the general population, restaurant and bar closures, gym closures,...