Vaccines Are Not Like Jam

8 min readNov 27, 2020

A recent article published in Bloomberg inspired me to take time away from my Ph.D. studies and write another short essay. While I am by no means an expert in the fields of epidemiology or public health, I feel more than qualified to critique the misuse of consumer behavior research as it pertains to addressing the Covid-19 pandemic.

Serendipity Led to Oxford/AstraZeneca Vaccine’s 90% Efficacy Rate

The half-dose/full dose puzzle in the results is explained.

medium.com

This article draws on a 2000 paper in the Journal of Personality and Social Psychology to make the following salacious claim:

“Sounds Strange, But There Could Be Too Many Vaccines”
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You can find the article at the following link: “Sounds Strange, But There Could Be Too Many Vaccines”

Off to a great start. Why might this be the case? The argument is as follows:

Behavioral economics shows that more choices in a supermarket setting may reduce consumption behavior. More specifically, the more jam flavors consumers are presented with lowers their willingness to buy jam.
Vaccines are like jam.

Virus Outbreak, Once in the Nation’s Middle, Gains Steam All Around

With cases and deaths rising fast, scientists say they worry about the virus’s course in the United States as…

medium.com

There are many vaccines proposed for Covid-19, and consumers are nervous about them.
Therefore consumers should get advice from their doctors as to which vaccine they should receive.

There’s a lot to unpack here. Let’s go through this point by point.

Point #1: More Choices Reduces Consumption

The paper cited by the Bloomberg journalist is by Sheena Iyengar of Columbia University, and Mark Lepper from Stanford University, and published in an A-tier journal. This is a solid source, and from what I gather the research is sound. It really is the case that presenting individuals with more jam options reduces their propensity to purchase jam.

This research has interesting implications for consumer behavior researchers and could help guide certain retailer stocking strategies. Think to your times at Costco — not many options, are there? You can find the paper linked below:

Point #2: Vaccines Are Like Jam

No. Next point.

Okay, I’ll flesh this out a bit more. While the author does note that vaccines are “more consequential and complicated” than jam, he assumes that they are sufficiently similar such that we can extrapolate from a study on jam to consumer responses to a Covid-19 vaccine. Not to hammer this point in too hard, but vaccines are not jam. Healthcare decisions more broadly have significant differences relative to consumer goods purchases in that they are, well, more consequential, and complicated.

The study cited explicitly does not look at high-impact decisions like getting a vaccine — only at decisions that are spur-of-the-moment, impulse-oriented, and of little importance. Should a jam not be to your taste, the worst-case scenario is a suboptimal flavor to your PB&J sandwich; should a vaccine not be to your taste, the worst-case scenario is death. While Iyengar & Lepper suggest that choice overload “may be further exacerbated” in high-impact choice contexts like alternative medicine, they do not investigate that intuition. This is the sort of line that gets thrown into the discussion section of a paper to make findings seem deeper than they actually are — to their credit, Iyengar & Lepper do not go so far as to actually claim this is the case, but their language is suggestive of such an effect in a way that journalists easily misinterpret.

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Points #3 & 4:

Who cares? Vaccines are not like jam. The entire premise of this article is based on a flawed notion of the generalizability of psychological studies. The recommendations offered by the author — get the vaccine your doctor tells you to get — are also no different from how people seem to get vaccines already. We are left with an article that uses the Covid-19 pandemic as an aesthetic backdrop to express unwarranted concern about vaccine uptake based on overgeneralized psychology findings.

Conclusion

This is but one example of psychological findings being generalized in unwarranted ways to high-risk contexts where misinterpretation could do real harm. The title and content of this article seem purpose-built to draw clicks at the expense of offering anything substantive to the discussion of the novel vaccines announced by Pfizer, Moderna, and Oxford. I would ask these news organizations to do better, but salacious misinterpretation appears to be fundamental to their business model.