Earlier in the week I did a post that included economist (and former Victoria University academic) Martin Lally’s sketch outline of an approach to thinking about applying cost-benefit analysis techniques to Covid vaccine “mandates”. In that post I included a few suggestions, questions, and thoughts on aspects of Lally’s note and the wider issue of coercion in a Covid context.

Since then, Lally has extended his note into a fuller short paper. I offered to make it more widely available here

A COST-BENEFIT ANALYSIS OF COVID-19 VACCINE MANDATES by Martin Lally

Here is his Abstract

Abstract

Covid-19 vaccine mandates for the general population must trade off the rights of those who object to being vaccinated against the costs that the unvaccinated impose upon the vaccinated, most particularly the increased risk to vaccinated people of death by covid-19.  This paper provides a methodology for doing so.  It is then applied to the case of New Zealand.  It reveals that even if the adverse impact of penalties on vaccine objectors (at least some of whom may have rational grounds for objecting) is as small as a reduction in their quality of life of 1% per year for a period of five years and the existence of unvaccinated people is entirely responsible for covid-19 infections amongst the vaccinated, the number of additional deaths amongst the vaccinated resulting from not adopting a vaccine mandate is too few to justify a policy of mandating.  However, unlike the general population, health workers come into frequent and close contact with large numbers of sick people, who are prime targets for covid-19, and therefore the vaccine mandate may be justified for these workers.

The paper largely speaks for itself. Lally lays out his assumptions (and sources) quite clearly, so anyone who disagrees can identify where (specifically) their disagreement arises and what alternative assumptions/approaches they would use.. As per the Abstract, he concludes that cost-benefit analysis does not support vaccine “mandates” in general, but one of the extensions of the earlier note is to explore the specific case of health care workers where his numbers suggest a cost-benefit analysis for compulsion may stack up. There is also a section at the end exploring the risks and incentives facing the young and the old faced with the offer of the vaccine.

To me, the most interesting part of the paper was his attempt to estimate how many lives (among the vaccinated) would need to be saved by coercing part of the population to be vaccinated to make such a policy pass a cost-benefit assessment. On his numbers (you can read the reasoning in the paper)

So, vaccine mandating would be warranted only if failure to do so leads to a pool of unvaccinated people who thereby induce at least 5,200 additional deaths from covid-19 amongst the vaccinated. 

And how likely is that?

I now consider whether at least 5,200 additional such deaths amongst the vaccinated could occur.  The worst case scenario for the 90% of the over 12s who vaccinate without mandating (4.2m*0.9 = 3.8m) is that they are all infected as a result of the existence of the unvaccinated people who might be induced into vaccinating.  In the absence of an effective vaccine, the proportion dying is the Infection Fatality Rate (IFR).  Recent surveys suggest figures of 0.3 – 0.4% for Europe and the Americas (Ioannidis, 2021, page 10), and 0.70% for Europe and 0.58% for the Americas (Meyerowitz-Katz and Merone, 2021, Figure 2).  The midpoint is about 0.5%, which implies 3.8m*0.005 = 19,000 dead.  However, this IFR relates to the entire population rather than only those over 12, and the latter IFR would be higher because the IFR is monotonically increasing with age.  Correction for this raises the IFR for the over 12s to about 0.60%.[1]  This implies 3.8m*0.006 = 23,000.  The vaccines reduce the risk of death by 85% to 88% on average over the first six months but rapidly wanes beyond that point (Nordstrom et al, 2021, Table 2 and Table 5).  If a booster is used at that point, the average reduction in the death rate would then be at least 85%.  This implies 23,000*(1 – 0.85) = 3,400 deaths amongst the vaccinated. 

This is the worst case.  It is inconceivable that all of the 3.8m vaccinated would be infected.  Amongst those infected, it is inconceivable that all would be infected as a result of the pool of unvaccinated people, i.e., some of the vaccinated would be infected even if there were no unvaccinated people because the vaccine does not eliminate the risk of its recipients transmitting the virus and therefore vaccinated people could be infected by other vaccinated people.  In fact, all of the vaccinated might become infected even if the unvaccinated pool did not exist, through the virus transmitting through the vaccinated.  Amongst those vaccinated who were infected as a result of the unvaccinated pool, some would be infected as a result of the vaccine objectors who will not succumb to the penalties, and a mandating policy cannot eliminate this group.  Taking account of all three of these points, the additional covid-19 deaths amongst the vaccinated in the absence of vaccine mandating would be significantly less than 3,400.

[1] Steyn et al (2021, page 14) cites age-related IFR data from Verity et al (2020, Table 1) and matches it to the New Zealand population proportions by age groups, which implies an IFR of 0.95%.  The same data can be used to estimate the IFR for the 12+ group, at 1.13%.  Both figures are unreliable because they are based upon IFR data from March 2020 from only one paper (Verity et al, 2020) rather than from recent surveys of the literature (as with Ioannidis, 2021 and Meyerowitz-Katz and Merone, 2021).  However, the increase of 19% (0.95% to 1.13%) can be applied to the preferred IFR estimate for the entire population of 0.5%, to yield 0.6% for the 12+ group.

It is quite simple, but illuminating, reasoning.

My point in running this post, and hosting Lally’s paper, is not to endorse all his reasoning or his conclusions. But it seemed like an interesting attempt to look at the issues rigorously – in a way that there is no sign officials and ministers have – which deserved to be available to a wider audience.