Avoidance Behavior

Every time I think of you
I always catch my breath
And I'm standing here
And you're miles away
And I'm wondering why you left
--John Waite

In an early April paper (full paper here), Jeffrey Harris, an MD and PhD Economist at MIT, presented evidence that the COVID-19 epidemic curve was already flattening in NYC. After disposing of several alternative explanations of why the flattening curves was a mirage (e.g., lack of testing, not accounting for asymptomatic cases, inhabitants fleeing the city, etc), he proceeds with a discussion of what was making the curve flatten.

He notes studies of social distancing measures, including a comparison of containment policies enacted by various cities during the 1918 Spanish Flu epidemic (Markel et al., 2007), suggest merits of spacing between people, particularly for prolonged periods of time.

Policymakers, of course, will be quick to credit their coercive lockdown measures with putting the necessary distance between people to reduce the threat of infection.

But Harris notes, "there is, however, another strand in the economics literature suggesting that people voluntary engage in avoidance behaviors once they fully perceive the risks of contagion." (p. 13) He notes various studies of past epidemics, including the 2009 H1N1 Swine Flu epidemic when there were no quarantines or lockdowns, where "economists could see no other explanation for their finding that the incidence of new cases fell well below the exponential path predicted from epidemiologists' classical models."

Harris suggests that, "in all of these cases, the critical ingredient in the public policy mix may have been the successful communication of consistent, clear, accurate and timely information to millions of individuals, who responded by taking action without government coercion. Put bluntly, what flattened the curve was no more than the naked truth."

This time around, policymakers who want to take credit for flattening the curve by draconian lockdown need to answer this question first: How do you know that what occurred was not primarily due to voluntary avoidance behavior? Once they understood the risks, why didn't people social distance themselves as they saw prudent?

Imagine where we'd be today if policymakers had merely shared information all along the way and then let the people decide what to do.

btw, Harris recently completed another interesting paper analyzing the subway's role in seeding the virus epidemic in NYC. Perhaps we'll discuss in an upcoming post.

Reference

Harris, J.E. (2020). The coronavirus epidemic curve is already flattening in New York City. National Bureau of Economic Research Working Paper No. 26917. April 3, 2020.

Markel, H., Lipman, H.B., Navarro, J.A., Sloan, A., Michalsen, J.R., Stern, A.M., & Cetron, M.S. (2007). Nonpharmaceutical interventions implemented by US cities during the 1918-1919 influenza pandemic. JAMA, 298: 644-654.