I’d add that your Veganuary participation numbers are likely way too generous. They come from a poll of the general public on participation and then scaling those numbers up to a broader population. However, opinion polling of this type famously overestimates the share of the population with rare characteristics due to mistakes, trolling, or in this case potentially social desirability bias.
Indeed, I have the impression that surveys estimating the share of vegans in the US population often getting about 5%, which is around the lizardman constant. Objective purchase data suggests that the number is more like 1%.
Nice to hear from you, Joseph! Great point. I have changed “participated in Veganuary” to “reported participating in Veganuary”, which was what I meant. I have added the following to:
The summary and discussion. “I would also add a question to the survey used to determine the number of people who participated in Veganuary which would check whether the respondents are replying in good faith. This is important because only a small fraction of the population participates in Veganuary, such that small errors matter. 4 % of Americans believe (actually, report believing) lizardmen are running the Earth”.
The section about the cost-effectiveness of Veganuary. “My effect size refers to people who reported participating in Veganuary. The number of people who actually participated may be significantly smaller. Veganuary concluded 25 M participated multiplying small fractions of participants in the surveyed countries by their populations. However, such fractions may be significantly explained by a few people mistakenly reporting their participation due to lack of attention or social desirability bias”.
I’d add that your Veganuary participation numbers are likely way too generous. They come from a poll of the general public on participation and then scaling those numbers up to a broader population. However, opinion polling of this type famously overestimates the share of the population with rare characteristics due to mistakes, trolling, or in this case potentially social desirability bias.
Indeed, I have the impression that surveys estimating the share of vegans in the US population often getting about 5%, which is around the lizardman constant. Objective purchase data suggests that the number is more like 1%.
Nice to hear from you, Joseph! Great point. I have changed “participated in Veganuary” to “reported participating in Veganuary”, which was what I meant. I have added the following to:
The summary and discussion. “I would also add a question to the survey used to determine the number of people who participated in Veganuary which would check whether the respondents are replying in good faith. This is important because only a small fraction of the population participates in Veganuary, such that small errors matter. 4 % of Americans believe (actually, report believing) lizardmen are running the Earth”.
The section about the cost-effectiveness of Veganuary. “My effect size refers to people who reported participating in Veganuary. The number of people who actually participated may be significantly smaller. Veganuary concluded 25 M participated multiplying small fractions of participants in the surveyed countries by their populations. However, such fractions may be significantly explained by a few people mistakenly reporting their participation due to lack of attention or social desirability bias”.