I agree on a meta level that the section on contraception shouldnât be here.
On the object level, this isnât the first time Iâve seen a charity analysis make the assumption that a problem can be completely solved if you multiply âcost to solve X% of the problemâ by 100/âX. This seems unlikely to be true in most cases, and is an important mistake to avoid.
For example, even if Guttmacher is correct that $9.4 billion will allow us to meet all unmet demand for contraceptives, contraceptives arenât always used correctly, and even when used correctly, they donât always work, so we wonât stop all 74 million unintended pregnancies. Also, not every unintended pregnancy leads to a child being born. And I suspect (from a brief skim of the report, I could be wrong here) that the $9.4 billion number involves some basic multiplication on Guttmacherâs part, without fully accounting for how difficult it is to reach different populations (in communities where contraceptives are forbidden, how much will it cost to change that policy?).
Itâs still valuable to estimate and round, but the âmultiply the number of people by the cost per personâ fallacy (is there a catchier name?) seems like it routinely underestimates the cost of fully âfixingâ a problem for reasons like these: Some % of your target population is hard to reach, and the thing that you think will always fix the problem only fixes it some % of the time.
Aaron, I think we agree that the contraception section is not the strongest part of the post. On your specific point though, I donât think itâs actually so bad to use the $9.4bn divided by 74 million.
You suspect that $9.4bn is calculated by looking at data from a much smaller sample and performing a simple extrapolation. So do I. But thatâs actually exactly what we wantâthis advice is intended for people donating thousands, not billions. (This point is what I was trying to get at with my note about more-expensive âlast-mileâ contraceptive needs).
Good points all. Yours was a reasonable estimate, but the topic made it a good way to discuss certain general problems with this type of estimate, which are often more prominent in estimates made by other people in other situations.
(Also, I didnât spot the âlast mileâ comment; sorry for missing that, and thanks for calling it to my attention.)
I agree on a meta level that the section on contraception shouldnât be here.
On the object level, this isnât the first time Iâve seen a charity analysis make the assumption that a problem can be completely solved if you multiply âcost to solve X% of the problemâ by 100/âX. This seems unlikely to be true in most cases, and is an important mistake to avoid.
For example, even if Guttmacher is correct that $9.4 billion will allow us to meet all unmet demand for contraceptives, contraceptives arenât always used correctly, and even when used correctly, they donât always work, so we wonât stop all 74 million unintended pregnancies. Also, not every unintended pregnancy leads to a child being born. And I suspect (from a brief skim of the report, I could be wrong here) that the $9.4 billion number involves some basic multiplication on Guttmacherâs part, without fully accounting for how difficult it is to reach different populations (in communities where contraceptives are forbidden, how much will it cost to change that policy?).
Itâs still valuable to estimate and round, but the âmultiply the number of people by the cost per personâ fallacy (is there a catchier name?) seems like it routinely underestimates the cost of fully âfixingâ a problem for reasons like these: Some % of your target population is hard to reach, and the thing that you think will always fix the problem only fixes it some % of the time.
Aaron, I think we agree that the contraception section is not the strongest part of the post. On your specific point though, I donât think itâs actually so bad to use the $9.4bn divided by 74 million.
You suspect that $9.4bn is calculated by looking at data from a much smaller sample and performing a simple extrapolation. So do I. But thatâs actually exactly what we wantâthis advice is intended for people donating thousands, not billions. (This point is what I was trying to get at with my note about more-expensive âlast-mileâ contraceptive needs).
Also remember Iâm aiming for a rough estimate.
Good points all. Yours was a reasonable estimate, but the topic made it a good way to discuss certain general problems with this type of estimate, which are often more prominent in estimates made by other people in other situations.
(Also, I didnât spot the âlast mileâ comment; sorry for missing that, and thanks for calling it to my attention.)