Non-technical summary

• We examined whether respondents selected more meat-free meals from certain types of menu, using data from an existing online hypothetical choice study (Brachem et al., 2019).
• Respondents selected more meat-free meals from hypothetical menus with more meat-free options and fewer fish/poultry options.  But we didn’t find a strong association for menus containing meat-analogue options.
• There are lots of important limitations to our analysis (e.g. not a randomized experiment, hypothetical choices – not actual behavior; meat-analogues in study not very appealing).
• Despite these limitations, we think the results point to:
  • the need for more research on the cost-effectiveness of advocating for meat-analogues compared to more meat-free options of any kind;
  • the potential harm to animal welfare if food-service providers include more fish and poultry dishes on their menus.

Summary

• Increasing consumption of meat-free meals can help reduce demand for factory farmed animal products and anthropogenic greenhouse gas emissions. But relatively little research has been done on how meat-free meal selection is influenced by menu options, such as the availability of meat-analogue options or different types of meat.
• We conducted a preregistered reanalysis of data from a series of hypothetical discrete choice experiments from Brachem et al. (2019). We explored how meat-free meal selection by 1348 respondents (mostly German students) varied across 26 different menus, depending on the number of meat-free options and whether any options contained fish/poultry meat or meat-analogues. Menus consisted of five options (of which, two or three were meat-free) and were composed using images and descriptions of actual dishes available at restaurants at the University of Göttingen.
• While our work was motivated by causal hypotheses, our reanalysis was limited to detecting correlations and not causal effects. Specific limitations include:
  • Examining hypotheses that the original study was not designed to evaluate.
  • De facto observational design, despite blinded randomization in the original study.
  • Possible non-random correlations between the presence of poultry/fish or meat-analogue menu options and the appealingness of other dishes.
  • Analysis of self-reported, hypothetical meal preferences, rather than actual behavior.
  • Meat-analogues in menus not reflecting prominent products attracting significant financial investment.
• Notwithstanding, our reanalysis found meat-free meal selection odds were:
  • higher among menus with an extra meat-free option (odds ratio of 2.3, 90% CI [1.8 to 3.0]).
  • lower among menus featuring poultry or fish options (odds ratio of 0.7, 90% CI [0.6 to 0.9]).
  • not significantly associated with the presence of meat-analogues on a menu (odds ratio of 1.2 (90% CI [0.9 to 1.6])) in our preregistered meat-analogue definition. Estimates varied across analogue definitions, but were never significantly different from 1.
• Despite the many limitations, these findings might slightly update our beliefs to the extent we believe correlations would be expected if causation were occurring.
• The poultry/fish option correlation highlights the potential for welfare losses from substitution towards small-bodied animals from menu changes as well as shifts in consumer preferences.
• Given the study didn’t feature very prominent meat analogues, the absence of a correlation in this reanalysis cannot credibly be used to refute a belief that high-quality analogues play an important role in reducing meat consumption. But when coupled with the strong correlation on an additional meat-free option, we think the reanalysis highlights the need for further research on the most effective ways to encourage selection of meat-free meals. It remains an open question whether, at the margin, it would be more cost-effective to advocate for more menu options featuring meat-analogues specifically, or for more meat-free options of any kind.

You can read the full post on the Rethink Priorities website, and also see the pre-print and code via the Open Science Framework..