The question
Animal welfare funders face a strategic question: should they invest in reducing the cost and improving the quality of plant-based alternatives (PBAs), or focus on other interventions like corporate welfare campaigns? The answer depends heavily on a factual question that's surprisingly hard to answer: how much do plant-based products actually substitute for animal products? This is the focus of The Unjournal's Plant-Based Substitution Pivotal Question.
If a 10% price reduction in Impossible Burgers leads many people to eat fewer chickens, that's a strong case for funding PBA development. If people who buy plant-based burgers are mostly substituting away from beef (not chicken), or if PBA buyers were already eating less meat, the case weakens considerably. The path from PBA improvements to animal welfare impact runs through these substitution effects.
Why this is hard to measure
Estimating substitution effects is notoriously difficult. We're interested in understanding substitution behavior more broadly—not precise "point" cross-price elasticities, which are unlikely to be constant across different price levels and contexts. Several key challenges complicate this:
- Price endogeneity: Stores don't vary prices randomly. They may reduce prices when they anticipate lower demand, which distorts observed price-quantity relationships. Standard econometric workarounds (instrumental variables, structural models) have significant limitations.
- Limited PBA data in key datasets: Major scanner datasets like Nielsen have limited coverage of plant-based alternatives, especially in the earlier years when these products were emerging. This restricts what questions can be answered with existing data.
- Long-term behavioral change: The most important substitution effects may operate over longer time horizons. As people see plant-based options as a feasible alternative, they may gradually alter their consumption patterns and even their identity around caring about animals—becoming "reducetarian," for example. Short-run elasticities may miss these dynamics.
- Functional form assumptions: Demand estimation requires strong assumptions about functional forms (AIDS, BLP models). Different specifications can yield very different elasticity estimates.
- Puzzling empirical patterns: Some studies find PBAs are complements to certain meats rather than substitutes—a counterintuitive result that likely reflects measurement difficulties rather than true consumer behavior. Bray et al. (2024) document another puzzle: IV and experimental estimates often diverge in opposite directions from naive OLS.
These measurement challenges mean we should interpret existing estimates cautiously, while still extracting what information we can. The workshop will discuss which methods are most trustworthy and what further research could help.
The evidence landscape
We've identified approximately 15 relevant empirical papers using various methods:
Scanner data studies
Using grocery purchase data (Nielsen, IRI) to estimate demand systems and cross-price elasticities. Methods include AIDS/QAIDS models, though identification strategies vary in rigor.
Hypothetical choice experiments
Survey-based discrete choice experiments asking consumers to choose between product bundles at different prices. Useful for scenarios not yet observed, but may not reflect real behavior.
Event studies
Examining what happens to meat purchases when households first buy PBAs. Useful descriptively, but causal interpretation requires strong assumptions about timing.
Field experiments
Randomized interventions in retail settings (e.g., moving PBAs to the meat aisle). Limited studies exist, but these offer the strongest causal evidence.
What we want to achieve
This workshop brings together agricultural economists, animal welfare researchers, and funders to:
- Review the evidence: Which studies are most credible? What can we actually conclude about substitution effects?
- Quantify uncertainty: What's a reasonable range for the cross-price elasticity between PBAs and chicken?
- Connect to decisions: Given current evidence, is PBA funding plausibly competitive with corporate campaigns?
- Identify research gaps: What study would most reduce uncertainty? Is it feasible?
Preliminary agenda
Note: This agenda is preliminary and will be refined based on participant input.
The workshop is planned for approximately 2.5–3 hours online, with segments designed for flexibility:
- Stakeholder Context (~15 min) — Why ACE and funders care about this question; current funding landscape
- Evidence Review (~30 min) — Overview of key studies; scanner data, choice experiments, methodological considerations
- Bray et al. Paper Discussion (~25 min) — Price endogeneity puzzles: why do instrumental variable and experimental estimates diverge? What does this mean for interpreting PBA research?
- Substitution Impact Discussion (~30 min) — Deep-dive on the focal question: effect of 10% PBA price reduction on chicken consumption
- Pivotal Questions & Beliefs Elicitation (~20 min) — Walking through the operationalized PBA pivotal questions; eliciting and discussing participant beliefs
- Animal Welfare ROI Panel (~30 min) — Comparing PBA funding to corporate campaigns; decision-relevant thresholds
Pivotal Questions
We've operationalized the key uncertainties into specific, answerable questions. These include:
- PBA_01 (Focal): If the price of high-quality plant-based hamburgers fell by 10%, how would global chicken consumption change?
- PBA_02: Is PBA research a good investment from an animal welfare perspective?
- PBA_03: Does the AW benefit of $100K to GFI exceed $100K to THL corporate campaigns?
Several of these are posted on Metaculus for community forecasting.