Meat reduction - How much can digital media and mass media help (Animal Ask)

The animal advocacy movement regularly invests resources into campaigns that aim to reduce people's consumption of meat and/or animal products. Many of these campaigns are conducted using digital media (e.g. social media ads) and/or mass media (e.g. radio, TV, newspapers).

In this report, we summarise the evidence on these campaigns. We conduct a cost-effectiveness analysis, drawing on the high-quality scientific studies that have been published over the past few years. This report builds on previous analyses of meat-reduction campaigns, which have been published by various researchers over the past decade. Our cost-effectiveness analysis focuses on what additional funding could achieve on the margin, ignoring fixed costs that are already being paid by existing animal advocacy organisations.

We address three main questions. These questions, and our current view on them, are as follows:

1. What impact might these campaigns have on the lives of animals? Given the scientific evidence we have available, our best guess is that these campaigns spare 3.7 animals per dollar. There is significant variance in our estimate - it is very possible that the campaigns actually have 0 impact, and it is somewhat possible that the campaigns have an impact that is several times higher than our best-guess estimate. Our best-guess estimate is in rough agreement with the cost-effectiveness estimated by previous researchers. We erred towards the conservative side when producing our calculations, so there are several important choices we made with which reasonable researchers could disagree.
2. Should the animal advocacy movement change the amount of resources invested in these campaigns? Based on our calculations, this campaign does not appear supremely cost-effective. On the other hand, the absolute impact of this campaign (3.7 animals per dollar) is quite reasonable, and the evidence base supporting this campaign is quite strong.
3. Could mass media campaigns in developing countries be a particularly impactful opportunity for these campaigns? We believe that radio and mass media campaigns in developing countries can justifiably form part of the movement's overall portfolio of outreach campaigns for meat reduction. However, we do not think it would be justified to put a disproportionately high amount of the movement's resources into radio campaigns in developing countries.
4. Could we create a win-win by jointly funding meat-reduction campaigns with climate-motivated funders? We find that climate funders (at least the funders strictly interested in climate and motivated primarily by cost-effectiveness) would not be keen to put large amounts of resources towards meat-reduction campaigns, even as a joint initiative. The reason is that meat-reduction campaigns appear to be a less cost-effective way to reduce greenhouse gas emissions than other options available to the climate movement.

Our conclusions are based on our cost-effectiveness analysis in which we calculated the expected number of fewer animals farmed per dollar spent on advertising (animals/USD). We calculated this for each of four different scenarios. We also produce rough upper and lower bounds to accompany our point estimates. The results are as follows:

1. Best-guess. This is our main scenario, and we think this scenario is the most likely of our four scenarios (~45%). Under this scenario, we estimate that meat-reduction outreach campaigns spare 3.7 animals/USD (-0.7 to 8.7).
2. Optimistic (but still plausible). This scenario optimistically assumes that meat-reduction advertisements are slightly more frequent (than in our best-guess estimate) at convincing people to reduce their meat intake. We think this scenario is plausible, but somewhat unlikely (~10%). Under this scenario, we estimate that meat-reduction outreach campaigns spare 9.1 animals/USD (5.3 to 13.6).
3. Optimistic + cheap + long-lasting (but still plausible). This scenario assumes a longer duration of diet change and a cheaper cost-per-engagement. We think this scenario is plausible, but unlikely (~5%). Under this scenario, we estimate that meat-reduction outreach campaigns spare 84.8 animals/USD (50.1 to 127.3).
4. Pessimistic (but still plausible). This scenario simply assumes that the effect of the intervention is zero. As Mathur et al (1) argue, many of the diet-change experiments are subject to various weaknesses (e.g. desirability biases). This means that a true effect of zero remains a real possibility (2). We think this scenario is somewhat likely (~40%). Under this scenario, we estimate that meat-reduction outreach campaigns spare 0 animals/USD.

Overall, our best guess is that meat-reduction outreach campaigns spare roughly 3.7 animals/USD. But there is a really good chance (our gut feel says a ~40% chance) that these campaigns have 0 impact, and there is a small chance (our gut feel says a ~15% chance) that the impact is several times larger than our best-guess. About 90% of this benefit comes from chickens and farmed fish. If you assume a typical lifespan of ~6 weeks for chickens and perhaps a bit longer for farmed fish, our best-guess estimate would correspond to roughly ~5 animal-months spared per dollar.

Our best-guess estimate suggests that meat reduction campaigns are somewhat less effective (~one-sixth as effective) as what previous cost-effectiveness analyses have concluded. Our analysis draws on a stronger evidence base than some previous analyses. We also make some assumptions and choices that tend to err on the conservative side, so reasonable people could conclude that the point estimate should be higher than we have concluded. We emphasise that there is plenty of variance across our four scenarios that capture the possibility for a more optimistic view.

Based on this analysis, we do not think that there is much reason for the animal advocacy movement to invest a substantially higher amount of resources into these campaigns.

The movement will probably continue funding these campaigns at roughly the current level of investment for the foreseeable future. So, it is probably worthwhile for the movement to fund a few more studies following the recommendations made by Mathur et al in the conclusion to their recent experimental report (2). In that report, Mathur et al found that the existing studies may be systematically overestimating the effects of meat-reduction campaigns, and they recommended that experimental studies be conducted in a way that measures actual consumption with a sufficient sample size while minimising social desirability bias.

On the other hand, we have mainly discussed the evidence for one-off interventions. In these interventions, participants see a message or advertisement only one time. However, it is also possible for campaigns to use mass media with the intention of showing the same message to each person multiple times. Repeat exposure might have a larger effect size than one-off exposure.