Here, I will present three main counterpoints to Peacock’s argument: first that the article presents a case against a narrow and high-bar version of the PTC hypothesis, second that the article missed some crucial existing evidence, and third that the article’s critiques of the evidence for the PTC hypothesis, though valid, must be kept in context.

The first and most important thing to clarify about the Rethink Priorities article is to clearly delineate what is – and is not – being said. The piece argues that fewer than 50% of today’s consumers would prefer PTC-equivalent alternative proteins over animal products. It does not argue –  and Peacock does not believe – that PTC are not important factors affecting food choice, or that investment in improving the PTC profiles of alternative proteins would not be productive.

Operationalising PTC

A major part of Peacock’s argument is that PTC equivalence have not been clearly defined and are difficult to operationalise. This prompts a worthy discussion: in my view, a PTC-equivalent animal product alternative is one which, compared to an animal product in the same category:

• Is the same or lower purchase price pound-for-pound. This is fairly straightforward – simply put, consumers are not paying more for the alternative than they would for the animal product.

• Performs at least as well in subjective tasting tests. This does not necessarily mean that people cannot tell the difference from meat (as in this study on filtered water), but that they do not prefer meat. Evidence for this could be no significant difference in subjective taste measures in a double-blind RCT.

• Is similarly available at the places people most commonly buy food (i.e. there is not a significantly lower proportion of major food retailers and service establishments offering the product)

If we are talking about all three of these conditions being met for one product, it is fair to say that there is no product which has achieved this yet. While there is some evidence for Impossible Burgers beating beef burgers in blind taste tests, and some cases where the price of plant-based options is lower than the animal product, I do not know of any case where both conditions are met – and, in both cases, the products are likely to be far less available (convenient) than their meat counterparts. 

The most important factors

Peacock proposes that, even if such a product existed today, fewer than 50% of consumers would choose it over its animal equivalent. Much of the discussion surrounding the publication has centred on how many people in the EAA community actually held the contrary view. I was not aware of holding this view myself, and I don’t think it’s a necessary entailment of holding the view that PTC are the most important food choice factors. 

Peacock has interpreted ‘most important’ to mean that, together, they account for most (i.e. more than 50%) of the total influence on our food choices. Another interpretation of ‘most important’ here implies that these factors are the top three factors affecting food choice – that is to say, they are more influential than other factors, even if they may not account for more than 50% of the total variance in food choice. 

Another way of interpreting the claim that PTC are the most important food choice factors is that these factors are necessary to reach a 50% market share, but not sufficient. That is to say, if, compared to animal products, alternatives are more expensive, worse-tasting, or less widely available, they are unlikely ever to reach a 50% market share, even if other conditions are also necessary to meet this threshold.

Peacock’s piece has prompted valuable consideration of what would happen if a PTC-equivalent product were achieved today. Even the most optimistic among us would surely believe that meat alternatives going from their current 1-2% market share of the overall market for meat and alternatives to 50% would still take at least a few years, given ingrained habits and social norms. 

That said, there has been a significant shift towards plant-based diets and alternative proteins over the last decade. Given that we may, in reality, be several years from a truly PTC-equivalent product, such products will likely arrive in markets where the norms and habits are more progressive than those of today.

I am pleased to say that, though he stands by many of his criticisms of the quality of the evidence, Peacock has somewhat revised up his assessment of the importance of price and taste in the light of further research I shared with him: the Food Choice Questionnaire (FCQ) literature. This is a self-reported measure which aims to measure the relative importance of 9 factors by asking participants to answer a series of questions in determining their food choice: sensory appeal, health, price, natural content, convenience, mood, weight control, ethical concern, and familiarity. The measure has been validated, adapted, and iterated in dozens of empirical studies which aimed to measure the relative importance of these 9 factors.

A 2018 systematic review of the FCQ literature aggregated FCQ data from 71 studies, and reported the average importance ratings for the nine criteria from five studies covering 26 different national samples. They find that ‘sensory appeal’ is the most important dimension on average for 15 (58%) of the samples, and second-most-important for a further 5 (19%). They find that ‘price’ is the most important factor for 6 (23%) countries, and second-most important for a further 7 (27%). 

It is worth noting that convenience is rated considerably lower – it is not the most important factor in any of the national samples, and is the second-most-important factor in just two. Notably, Peacock’s piece for Rethink Priorities acknowledges that convenience is the vaguest and most difficult-to-operationalise of the PTC trifecta, and his piece contains several helpful ways in which convenience could be defined and operationalised. Bruce Friedrich, Executive Director of GFI, has commented that GFI’s strategy tends to focus mostly on improving price and taste.

It is also worth noting that the health factor also stands out as important by the same measure. Health was ranked first in 8% of samples, and second in a further 31%. Peacock has done the field a service in prompting us to consider this: for many consumers, health is going to be an important factor affecting their choices, and may well be another necessary condition for replacing meat. Interestingly, health has been a common angle of attack on alternative proteins – although meat alternatives tend to be healthier than meat in many respects, the meat industry has funded messaging to position meat alternatives as ultra-processed, with the misleading implication that they are therefore unhealthy. 

That said, alternative protein producers should proceed with caution: emphasising the healthiness of a food product is often taken to imply that it is not tasty. There is some evidence that plant-based products with a health-focused label sell worse than those with a taste-focused label. Remarkably, adding a health-focused appeared to hurt sales compared to having no label at all. It seems that consumers interpret most health labels (‘low fat’, ‘low salt’) to mean ‘not very tasty’. 

The final point to be made here relates to some technical critiques Peacock offers of the evidence for the importance of PTC. In particular, Peacock argues that the evidence for PTC is self-reported, and is therefore subject to the well-documented unreliability of self-reporting. He also argues that the evidence is subject to the ecological fallacy, which is to say that price and taste having the highest average ratings does not necessarily imply these factors together are the most important for most people. 

On the first point, I agree: there are certainly limits to self-reported data. Research participants may be motivated to over-report pro-social behaviour, they may forget things, be affected by their mood, or simply lack the introspection to give accurate answers. I think it is likely that, in this context, people over-report the importance of healthiness (since people tend to be optimistic about their health-related behaviours) and under-report the importance of convenience and familiarity (since both could clearly be taken for granted or not consciously acknowledged as a factor in food choice). Clearly, self-report is fallible – those criticisms notwithstanding, if people consistently self-report that taste and price are important to their food choices, that is some evidence that those factors are indeed important to them, however imperfect.

On the second point about the ecological fallacy, I am more inclined to push back. Peacock astutely and accurately identifies the ecological fallacy here: specifically, the proposition ‘price and taste are the most important factors on average’ is different from the proposition ‘price and taste are the most important factors for most people’. I grant this, and Peacock may be correct that the latter proposition is not true – but it is not clear that the latter proposition is more important than the former. If they are different, should we focus on advancing the factors which are the most important to food choice on average, or the factors which are most important to food choice for the highest percentage of people? Again, I think the critique is valid, but does not undermine the importance of advancing the taste and price of alternative proteins.