Joel Tan

Founder @ CEARCH
1302 karmaJoined Aug 2022


Founder of the Centre for Exploratory Altruism Research (CEARCH), a Charity Entrepreneurship-incubated organization doing cause prioritization research.

Once a civil servant, and then a consultant specializing in political, economic and policy research. Recovering PPEist who overdosed on meta-ethics.


CEARCH: Research Methodology & Results


Topic contributions

Hi Nick!

Yep, that's definitely a concern for governments (same with other policy interventions for nutrition). For funders - to be fair, that's not much different from direct delivery (e.g. for vaccinations or contraception, we can't really know the impact until we finish our M&E and see the uptake rates/disease rates change)

Hi Mo,

I don't think I read that part of Michael's thesis before, but it does look interesting!

In general, I think it's fairly arbitrary what a cause is - an intervention/solution can also be reframed as a problem (and hence a cause) through negation (e.g. physical activity is a preventative solution to various diseases like cardiovascular disease or diabetes, and in a real sense physical inactivity is a problem; having an ALLFED-style resilient food supply is a mitigatory solution to nuclear winter - even if we can't prevent nuclear exchange, we can perhaps stop billions from dying from famine - and in that sense lack of foods capable of growing in abrupt sunlight reduction scenarios is a problem).

Yep, that's what Jeroen submitted, and he posted it to the forum after. I think it's a really useful perspective to have. In GHD, we already have various risk factors that we can address to solve multiple diseases (e.g. hypertension for coronary heart disease, stroke, kidney disease etc), and it makes sense to apply this perspective more broadly.

Thanks for the thoughtful comment!

(1) On the evidence base for mass media interventions: Our choice to prioritize mass media (and so attempt more detailed modelling) was based on it (a) looking good in cost-effectiveness at a a shallower research stage with a less; (b) being recommended by the WHO as the most cost-effective intervention for promoting physical activity; and (c) generally, mass media interventions being 2nd only to policy in cheap scalability.

We relied on the study you cited (Abioye, Hajifathalian & Danaei), and took into consideration all three meta-analyses (impact on sedentary behaviour, sufficient walking, and sufficient physical activity), while discounting based on the degree to which measured outcome is dissimilar to GBD/WHO definitions of sufficient physical activity (>= 600 METs minutes per week). We did not exclude the sedentary meta-analysis results based on the fact that its reliant on a low quality outlier, but did perform our own analysis, to discount it (and the other meta-analyses) on the basis of underlying study quality (especially with respect to endogeneity) and publication bias.

We also considered whether the studies being from high-income countries biases the result (n.b. on the one hand, ageing high income countries are older and more sedentary, which implies a larger group of potential beneficiaries and greater population-level effect size; on the other hand, as Rosie Bettle of FP notes in her report on mass media interventions, its potentially the case that basic healthcare knowledge is more lacking in poorer countries, so you can - as with vaccine uptake - increase uptake there in a way).

Overall, we do think there's is an effect, but it's highly uncertain, and there's a real chance it's zero. For more details, see the ultra-long (and fairly tedious) discussion in this cell (Tractability:B12) of the CEA.

(2) Built environment changes: We did take a look at this option (see Annex A in our CEA for a qualitative discussion of the available intervention options, and the relevant evidence base/expert feedback). We ultimately prioritized mass media (for reasons discussed above), but I do think such environment changes will be substantially more impactful but also much, much harder.

For one, if we're talking about not just high-income countries but LMICs, the situation is very different. Zoning is just much less a factor than in the rich world (they may not have much on the books, and what's on the books may not be enforced), so the problem they face isn't the one that the US/UK etc face and which YIMBYs are trying to solve. Their major cities are also extremely dense, and people have low vehicle ownership rates (but worse congestion and air pollution). Making these cities more walkable isn't just a matter of allowing dense housing, but spending a lot of money to improve public transport, solving air pollution etc, and that's a fundamentally much harder ask for poor countries.

I used Abioye, Hajifathalian & Danaei on mass media, and Kang et al on pedometers. We also looked at a bunch of other interventions (e.g. built environment measures, digital interventions, point-of-decision prompts like posters by stairs, etc) - do take a look at Annex A in our CEA for a qualitative discussion of the available intervention options, the relevant evidence base/expert feedback, and why we prioritized government public education campaigns.

You can always reach out via the forum!


Thoughts about EGI vs policy advocacy, Joey? Odds of success will should be lower but expected impact higher than either DD/EGI. For learning value I imagine it's something in between - strong emphasis on communications, but you're also working in a local LMIC context, and forced to adapt, unlike EGI attempts based in your home country.

You might want to reach out to Akhil Bansal, who was a Schmidt officer on AMR and now runs an AMR funding circle. He'll be very up to date on this issue.

While the idea of moral licensing makes sense to me in theory, I'm not too persuaded by the empirical evidence, at least from the cited meta-analysis - the publication bias is enormous, as the authors note.

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