Thanks for making these changes and responding to my concerns! Also great to hear that HLI is doing a more in-depth analysis, that will be exciting to read.
With regards to the projections, it seems to me you just made up the number 10 000 participants? As in, there is no justification for why you chose this value. Perhaps I am missing something here, but it feels like without further context this projection is pretty meaningless.
My guess is that a WhatsApp-based MH intervention would be almost arbitrarily scalable. 10 000 participants ($300,000) may reflect the scale of the grants they are looking for.
I’ll rewrite completely because I didn’t explain myself very clearly
10,000 participants is possible since they are using Whatsapp, in a large country, and recruiting users does not seem to be a bottleneck
10,000 participants is relevant as it represents the scale they might hope to expand to at the next stage
Presumably they used the number 10,000 to estimate the cost-per-treatment by finding the marginal cost per treatment and adding 1⁄10,000th of their expected fixed costs.
So if they were to expand to 100,000 or 1,000,000 participants, the cost-per-treatment would be even lower.
I hope this is not what is happening. It’s at best naive. This assumes no issues will crop up during scaling, that “fixed” costs are indeed fixed (they rarely are) and that the marginal cost per treatment will fall (this is a reasonable first approximation, but it’s by no means guaranteed). A maximally optimistic estimate IMO. I don’t think one should claim future improvements in cost effectiveness when there are so many incredibly uncertain parameters in play.
My concrete suggestion would be to rather write something like: “We hope to reach 10 000 participants next year with our current infrastructure, which might further improve our cost-effectiveness.”
Thanks for making these changes and responding to my concerns!
Also great to hear that HLI is doing a more in-depth analysis, that will be exciting to read.
With regards to the projections, it seems to me you just made up the number 10 000 participants? As in, there is no justification for why you chose this value. Perhaps I am missing something here, but it feels like without further context this projection is pretty meaningless.
My guess is that a WhatsApp-based MH intervention would be almost arbitrarily scalable. 10 000 participants ($300,000) may reflect the scale of the grants they are looking for.
I don’t understand what you are saying here, could you elaborate?
I’ll rewrite completely because I didn’t explain myself very clearly
10,000 participants is possible since they are using Whatsapp, in a large country, and recruiting users does not seem to be a bottleneck
10,000 participants is relevant as it represents the scale they might hope to expand to at the next stage
Presumably they used the number 10,000 to estimate the cost-per-treatment by finding the marginal cost per treatment and adding 1⁄10,000th of their expected fixed costs.
So if they were to expand to 100,000 or 1,000,000 participants, the cost-per-treatment would be even lower.
I hope this is not what is happening. It’s at best naive. This assumes no issues will crop up during scaling, that “fixed” costs are indeed fixed (they rarely are) and that the marginal cost per treatment will fall (this is a reasonable first approximation, but it’s by no means guaranteed). A maximally optimistic estimate IMO. I don’t think one should claim future improvements in cost effectiveness when there are so many incredibly uncertain parameters in play.
My concrete suggestion would be to rather write something like: “We hope to reach 10 000 participants next year with our current infrastructure, which might further improve our cost-effectiveness.”