Bittersweet

There is this bittersweet moment that all statisticians and data scientists experience in any successful project. It's the moment where we finally cleared the forest, and saw the light. It's the moment for claiming our prize – a simple, coherent story explaining the data mess. Now that we've got the map of the forest, it's simple to retrace the path to the light. We wonder how we took all those wrong turns. The taste is bittersweet.

***

I thought about all that while hearing the know-it-all pundits shouting at public health officials, epidemiologists, and politicians for not acting fast enough, for ignoring the dangers, for letting the pandemic grow so rapidly.

One simply cannot look at the coronavirus growth curve today and complain about a decision made two weeks ago; that was two weeks ago when we didn't have the two weeks of data we do today. Everything always feels simple after you've seen the data you didn't have.

***

Consider two countries A and B. Country A gets its first case, and eventually the virus arrives at country B. When country A made decisions related to containment, it had only five days of data. The cost of containment is likely economic collapse. It chose to wait and see.

Then, the case counts started to jump, and country A took more drastic action after 10 days. In this period, Country B started seeing its first cases. It faced exactly the same dilemma as Country A. Case counts were low by day 5 and growing slowly. Drastic measures would destroy the economy. It chose a wait-and-see approach.... until the cases began to rise sharply.

Country B blamed country A for not moving fast enough to contain the virus, thus allowing it to spread. But on day 5, it was not certain, not even close, with the limited initial data, that the contagion would be become serious. The only reason why Country B felt wronged is because the virus got there later. Even with the benefit of more data, Country B mimicked Country A's decisions. In fact, one can say Country B's action validated Country A's earlier decision to stall.

***

When we finally emerge from this crisis, we will reach that bittersweet moment. We've conquered the virus, but we'd lament that we didn't do it sooner. That's the deceptive power of hindsight.