Oster published a dissertation for her economics Ph.D. from Harvard University, which suggested that the unusually high ratio of men to women in China was partially due to the effects of the hepatitis B virus. "Hepatitis B and the Case of the Missing Women," pointed to findings that suggested areas with high hepatitis B rates tended to have higher male-to female birth ratios. Oster argued that the fact that hepatitis B can cause a woman to conceive male children more often than female, accounted for a bulk of the "missing women" in Amartya Sen's 1990 essay, "More Than 100 Million Women Are Missing." Oster noted that the use of hepatitis B vaccine in 1982 led to a sharp decline in the male-to-female birth ratio. Sen's essay had attributed the "missing women" to societal discrimination against girls and women in the form of the allocation of health, educational, and food resources. In April 2008, Oster released a working paper "Hepatitis B Does Not Explain Male-Biased Sex Ratios in China" in which she evaluated new data, which showed that her original research was incorrect. Freakonomics author Steven Levitt saw this as a sign of integrity.

In April 2020, with nothing else to do, my family took an enormous number of hikes. We all wore cloth masks that I had made myself. We had a family hand signal, which the person in the front would use if someone was approaching on the trail and we needed to put on our masks. Once, when another child got too close to my then-4-year-old son on a bridge, he yelled at her “SOCIAL DISTANCING!”

These precautions were totally misguided. In April 2020, no one got the coronavirus from passing someone else hiking. Outdoor transmission was vanishingly rare. Our cloth masks made out of old bandanas wouldn’t have done anything, anyway. But the thing is: We didn’t know.

[My bold to replace italics in the original.]

I have been reflecting on this lack of knowledge thanks to a class I’m co-teaching at Brown University on COVID. We’ve spent several lectures reliving the first year of the pandemic, discussing the many important choices we had to make under conditions of tremendous uncertainty.

Another example: When the vaccines came out, we lacked definitive data on the relative efficacies of the Johnson & Johnson shot versus the mRNA options from Pfizer and Moderna. The mRNA vaccines have won out. But at the time, many people in public health were either neutral or expressed a J&J preference. This misstep wasn’t nefarious. It was the result of uncertainty.

Remember when the public-health community had to spend a lot of time and resources urging Americans not to inject themselves with bleach? That was bad. Misinformation was, and remains, a huge problem. But most errors were made by people who were working in earnest for the good of society.

The people who got it right, for whatever reason, may want to gloat.

We have to put these fights aside and declare a pandemic amnesty. We can leave out the willful purveyors of actual misinformation while forgiving the hard calls that people had no choice but to make with imperfect knowledge. Los Angeles County closed its beaches in summer 2020. Ex post facto, this makes no more sense than my family’s masked hiking trips. But we need to learn from our mistakes and then let them go. We need to forgive the attacks, too.