Important paper on coronavirus death rates suggests effects of govt measures (eg distancing) have been “substantially” overstated HT @tylercowen minneapolisfed.org/research/sr/sr… 
Paper suggests death rates rose & fell mostly regardless of govt actions: “We are concerned that [previous] studies may substantially overstate the role of govt-mandated NPIs [non-pharmaceutical interventions] in reducing disease transmission due to an omitted variable bias”
Three possible “omitted variables”: 1. “Humans spontaneously take action to avoid disease transmission once an epidemic breaks out”, & this behaviour change is big & consistent enough to produce roughly the same decline in death rates at the same time everywhere...
2. “The network structure of human interactions naturally leads to a slowdown in disease transmission faster than would be predicted from a simple epidemiological model in which the population interacts uniformly with each other”, ie the most interactive ppl have already had it..
Or 3. “Unexplained natural forces might account for the observed decline in transmission rates for Covid-19”, ie, the theory of existing immunity from common cold or other previous undetected coronaviruses
