Nick, on behalf of our team at Rethink Priorities, I’d like to thank you for engaging with our work and sharing your insights. We really appreciate it! You raise some excellent points, and I’d like to respond to them in turn.

HSS is not neglected:

• I’d agree that looking at total dollar spending on HSS doesn’t by itself give a clear sense of neglectedness. While HSS has certainly been central to the discourse, I’d argue it has often been more rhetoric than reality. Much of the ~$100B labeled as “HSS” may in practice have gone toward narrow or superficial fixes, at least that’s something I’ve seen noted repeatedly in the literature. In some yet-unpublished follow-up work, we’ve also tried to relate those spending figures to the share of the health burden attributable to weak health systems, though doing so is quite tricky and comes with considerable uncertainty.

RP’s best Interventions are barely HSS and focus on Health Workers:

• That’s a good point, and I’d clarify that we don’t necessarily think interventions like IMCI, CHW expansion, or community scorecards are the best or most impactful HSS interventions overall. Rather, they are the ones where decent evidence on cost-effectiveness was most readily available, which made them rise to the top in our initial analysis. There may well be higher-level or more systemic interventions that could deliver larger or more sustained health gains, but they often lack the kind of robust evaluation data we need to assess them confidently. In that sense, the ranking reflects the current evidence base more than an absolute judgment about where the biggest opportunities lie.
• I share your impression that some nice-sounding or fuzzy interventions can be hard to see as meaningfully improving things. That said, governance is one area I strongly believe in (see also what I wrote on governance further below). While its impact can be difficult to capture from the bottom up when looking only at individual impact evaluations, it becomes more visible from the top down when examining which factors plausibly contributed most to meaningful health systems strengthening in a country over time. This is also something I found quite convincing in the work of Exemplars in Global Health and the Good Health at Low Cost study.

Cost-Effectiveness of HSS interventions can and should be measured:

• Regarding the “narrow outcomes,” I’d be thrilled if more HSS evaluations reported actual health outcomes (or direct effects on household finances), but as you’ve noted, that’s not always feasible or practical. In the meantime, we can focus on intermediate outputs, but I see two main concerns. First, these outputs are often so far upstream that linking them to health impact requires a lot of guesswork and assumptions. Second, they often capture only a small slice of the system, even though the reform affected much more, making it hard to understand the broader effects. For example, an evaluation might report that a procurement reform reduced drug prices but provide no data on whether availability or stockouts improved, even though that was a key reform goal. And when prices change, the downstream and general equilibrium effects can be complex and hard to anticipate. I’m often surprised by how little is measured around big, system-wide reforms, given how much they can shift across the system.
• I’m very sympathetic to the idea that RCTs could be used more often for HSS interventions, and I think they are technically feasible in many cases. However, I do believe RCTs in the context of HSS tend to be more complicated and expensive, especially when multiple interventions are rolled out simultaneously, timelines are long, and there are potential spillover or general equilibrium effects, typically more so than in vertical programs. I also suspect it’s often a public goods problem: the benefits of generating generalizable evidence mostly accrue to others, while the costs and burdens of implementing the reform in a way that allows an RCT can largely fall on the implementing government. At least, that was my impression when I was involved in evaluating different reforms in Ethiopia, where the government seemed more keen on rolling things out quickly and evenly rather than on randomizing across districts and making some people wait longer for the reform.

Context matters - Country >>> Intervention:

• I strongly agree with you that the country context often matters more than the specific intervention. I think many of the classical success stories, like Bangladesh, Rwanda, or Ethiopia, are ultimately stories of strong governance and sustained political commitment. That commitment manifested in a wide range of ways, from institutional reforms to close collaboration with NGOs. In those contexts, my impression is often that any specific intervention mattered less than the broader enabling environment.
• I also agree with your point about not overinterpreting success in high-functioning countries. As you noted, interventions like microfinance didn’t translate well from Bangladesh to other settings, and I think the same caution is warranted for health systems. That said, I still see a lot of value in studying what worked and where, especially to understand the combination of factors that enabled success in specific contexts.

IMCI and other guidelines have enormous potential:

• What you wrote makes a lot of sense to me and aligns with my general intuition about the importance of guideline-based healthcare. It’s not an area I’ve looked into closely myself, so I really appreciate the insight.

Community Health workers are often not cost-effective:

• I agree with you that community health workers (CHWs) are unlikely to be among the most cost-effective interventions. We noted in the report that “CHW interventions are likely to require large amounts of ongoing financial support, and do not offer a clear path toward highly cost-effective or leveraged interventions”, which was meant to reflect this view.
• That said, if we look beyond the immediate, short-run effects of CHWs (such as patients treated), their longer-term contributions may be quite substantial. In Bangladesh, for example, CHWs played a transformative role not only in delivering services but also in shifting norms around family planning, increasing female education, and building trust in the formal healthcare system, all of which helped increase demand for institutional care over time. Those broader effects may not show up in short-term cost-effectiveness metrics, but I believe they are likely substantial (though I can’t point to concrete numbers). Exemplars in Global Health illustrate this nicely in their case studies, e.g. here and here.

LMH is far more well known and better funded than Living Goods:

• We only had time to look at LMH at a very superficial level, so you might be right about that.

Transitioning to government ownership is a risky bet - that might sometimes be worth it:

• I really appreciate this insight from someone experienced on the ground. To be clear, we have not spent any time coming up with a probability of success for this pathway, and I agree that assuming a smooth transition to government ownership would be naive. At best, I think of this as a high-risk, potentially high-reward opportunity, and one that might only make sense if there’s a particularly strong implementing partner (like LMH), unusually strong government buy-in, and a clear reason to believe philanthropic support would be catalytic rather than duplicative. But it’s certainly not a “default” safe bet.

Supply Chains interventions have largely failed:

• We actually did some (unpublished) follow-up research that focused more heavily on supply chain interventions, and it left us more cautious as well. The evidence for large-scale structural reforms seems quite mixed, and we struggled to find clear, well-documented success stories. The USAID-Chemonics project you mentioned illustrates this challenge well, though it’s hard to disentangle whether the issue stemmed primarily from the inherent complexity of supply chain reform or from shortcomings in the program’s design and execution.
• Regarding the need for last-mile delivery interventions, you probably have a better sense of the situation on the ground than we do. That said, some recent publications make me think that the problem isn’t quite solved yet. For example, a recent last-mile delivery intervention for COVID-19 vaccines in Sierra Leone increased vaccination rates by 26 percentage points within 48-72 hours (Meriggi et al., 2024). Moreover, the Gates Foundation still seems pretty active in supporting last-mile delivery interventions (e.g., here and here), which suggests that they still see meaningful gaps to address. We haven’t reviewed RidersForHealth in detail, so I can’t speak to their specific model.

Again, thanks a lot for engaging with our report!

I agree this is most likely a lower bound - we tried to emphasize this in the report. 

I was not aware of the theory that fungal infections are the primary cause of cancer - many thanks for sharing!

Yes, indeed, what we call 'confidence interval' in our report is better described by the term 'credible interval'. 

We chose to use with the term 'confidence interval' because my impression is that this is the more commonly used and understood terminology within EA specifically, but also global health in general - even though it is not technically entirely accurate.

Thanks, David! Nice post, and interesting to see a range of options pointed out by different people.

Some suggestions touch upon topics we've done research on at Rethink Priorities. For example, we have a report on charter cities and one on improving weather forecasting for agriculture for anyone who's interested in more detail. We're also planning to publish something on improving scientific research capacity in sub-Saharan Africa soon.

Hi Oscar, Thanks for your comment. I've actually read your post and thought your points are valid! The reason why it is not mentioned in our report is that we agreed with GiveWell that this aspect of discount rates would be out of scope for this particular report (which does not mean it is not important).

I'm neither an expert on aging, nor a biologist (only a silent consumer of the aging literature and stuff that Prof. David Sinclair says about the topic). Just wanted to say that I'd love to read a post on this!

Thanks a lot for your elaborate and thoughtful comment! A quick reaction to your thoughts:

1. Unfortunately, the literature we reviewed did not seem to be very clear-cut on the question of when exactly to use prizes vs. grants (or other incentives). Intuitively, I'd agree that a prize makes sense (vs. a grant) when identifying a suitable candidate is difficult. To me, this point is already broadly covered by "when the goal is clear, but the path to achieving it is not", as when you don't know how to solve something, you may also not know who could solve it. Could you give an example of how moral hazard can come into play?
2. Thanks for pointing out more design issues!  Our report is definitely not exhaustive with regard to how best to design a prize. I  don't fully remember why we did not include the specific design issues you mention, but it is likely because we didn't find good (quasi-) experimental literature on them. Case studies might be useful here.
3. I agree that recognition prizes are likely less useful than inducement prizes when you have a very specific problem to be solved. I think recognition prizes are useful when you generally want to increase research and attention to a specific topic, which can help reveal new problems to be solved that you didn't even think of in the first place. 
4. I think I share your intuition here. I can definitely imagine that financial incentives might potentially be more important in smaller, unglamorous prizes. We focused on large innovation prizes in our report, so I am not sure what's the most effective incentive structure for small prizes. 

Yes, you're right, that could definitely be the case. We have not looked into that.

Good examples with auction theory and the deferred acceptance algorithm! I've been frustrated for a while that my municipality doesn't want to try out the deferred acceptance mechanism for school/kindergarten choice :)

Thank you so much for sharing additional literature! I really appreciate the effort.

As far as I can tell from a skimming these articles, they seem to be mostly theoretical or modeling studies. 

In our report, we mainly focused on the empirical (and especially the (quasi-)experimental) literature in our report because (1) we wanted to understand how well prizes work in practice, and (2) our impression was that the theoretical literature on prizes seemed somewhat too  removed from the way that typical large prizes are implemented  in real life.

Do you have any advice for individuals who are interested in starting a charity, but who cannot or do not want to go through the CE incubation program (e.g. because their application was rejected, or because they didn't find the time to participate in the program, or because they do not fully agree with CE's approach)?