I have tried to post Veganuary's reply twice now and the spam-blocker immediately deletes it. I do not have the intercom icon so I don't know how to contact the admin to get this resolved. I hope they will see this message and post my comment.

I am trying to comment on Vasco's critical post about Veganuary but it has been deleted as spam twice. I am from Veganuary and we surely have a right to reply to this post. I do not have the icon you said I can use to message you.

Toni Vernelli

We are grateful to Vasco for sharing this analysis with us prior to publication, for delaying in order to give us time to respond, and also for using his time to quantitatively explore the most impactful way to help animals. 

While we appreciate Vasco’s intentions in producing this analysis, we believe there are reasons to be much more optimistic about Veganuary’s impact. We feel Vasco’s results reflect arbitrary assumptions based on his priors, rather than high-quality evidence about our campaign’s effectiveness.

Vasco’s calculations imply that Veganuary counterfactually reduced meat consumption by an extraordinarily small amount – the equivalent of just 1.3K metric tonnes.  Around half of this is assumed to come from 25M direct pledge participants – who he assumes counterfactually reduce lifetime meat consumption by the equivalent of just 25g each (around 0.03% of annual meat consumption in the UK in 2021).  The other half comes from all Veganuary’s other work, including our corporate engagement work, which we believe reaches many more people.

We regrettably think Vasco made very big adjustments that reflect his pessimism about our impact, but neither the magnitude of these judgements nor the degree of underlying uncertainty is communicated very clearly in his post. Crucially, Vasco arbitrarily assumed that Veganuary’s impact on pledge participants is 10x lower than the average effect size from the Green et al (2024) meta-analysis. Vasco’s justification of this is that our spend per pledge participant (c.$0.13) is probably a lot lower than the interventions in the Green et al (2024) meta-analysis. 

We believe Veganuary might be a victim of its own success here.  Being able to reach millions of people at low cost by creatively leveraging media and inspiring improved retail and food service offerings is a potential signal of effectiveness – but Vasco appears to have used this as a negative signal about our impact.

Vasco also assumed that the counterfactual impact of our non-pledge work is about the same as our work to inspire pledge participation.  While this is hard to know for sure, we believe the counterfactual impact of our corporate engagement work to inspire more, better, and highly visible plant-based offerings in retailers and food service could be several times higher than arising from pledge participants.

We accept that properly measuring the counterfactual impact of interventions on animal product consumption is exceptionally hard, even more so with campaigns like Veganuary that gain national media coverage and influence product offerings at major retailers and food service outlets. We’d love to be able to allocate more resources towards measuring our impact.  We aren’t yet in a position to provide quantitative estimates we feel we can stand by, but the following results make us optimistic our impact is likely to be much higher than what Vasco set out in his analysis:

• Meat reduction data from Germany’s Statistical Office: The German Federal Statistical Office (Destatis) published that based on scanner data from German food retailers, 29.4% less meat was purchased in January 2024 than in December 2023. Compared to the 2023 annual average, meat sales in January 2024 were 12.5% lower than the previous 12 months. Compared to the 2022 annual average, meat sales in January 2023 were 14.3% lower than the previous 12 months.
• New Research from the University of Exeter suggests that taking part in Veganuary leads to sustained reductions in meat consumption and can also produce fundamental shifts in people’s attitudes towards meat and their own self-identity as a meat-eater. Full study here.
• Kantar data from the UK shows that, for 832K people who gave up animal products for the first time in January 2019, sustained reductions in animal product purchases over the following six months totalled 4,452,603 kg – equivalent to sparing 3.6 million animals by our calculations.  While Veganuary cannot take all the counterfactual credit for these diet changes, it is striking how the estimated aggregate reduction in animal product consumption from pledge participants in just one country in 2019 is considerably higher than Vasco’s assumptions.
• Participant surveys consistently show long-term dietary changes, with over 80% of surveyed email participants reducing animal product consumption by at least half, creating compounding benefits over time. We do of course recognise the selection bias in participant surveys, which is why we commissioned the Kantar study in 2019 and have switched to nationally representative surveys to better measure our reach.

While we are grateful for Vasco’s commitment to seeking the most cost-effective way to help animals, we think he has made arbitrary judgements that make Veganuary look considerably less cost-effective than we believe it is and has not clearly explained these judgements in a way is helpful for readers. 

While we accept it is exceptionally difficult to measure the impact of interventions like Veganuary, which use the diet change element of its work to drive progress through corporate engagement, we welcome ideas from readers on ideas of how we might be able to do this (and resources to help run such studies).  We also welcome serious attempts to measure our effectiveness that legibly explain key cruxes/judgements/uncertainties, and credible suggestions on how we can improve our effectiveness (acknowledging we operate under constraints given our name, branding, and supporter base).   

Toni Vernelli, International Head of Communications, Veganuary