Mental health interventions vs life-saving charities
The other important comparison to make is between the life-improving mental health interventions, e.g. StrongMinds, and GiveWell’s recommended life-saving interventions, such as the Against Malaria Foundation (AMF).
How should we value a life?
This analysis is not very straightforward. First, there are different philosophical views about the badness of an individual’s death, as noted by Plant (2016). Second, a thorough analysis would also need to take into account the ‘other-regarding value’ of lives, the value saving a life has for everyone else. To assess this we’d need to account for the grief to friends and family saving a life prevents, as well as some complicated and potentially disturbing factors that are not usually considered, such as the meat eater problem and whether or not the Earth is under- or overpopulated.
We will put the complexities of the other-regarding value of lives to one side, and use the (simple) life comparative account of the badness of death, on which the value of saving a life is the total well-being the person would have had if they’d lived.
Evaluating AMF - what is a life worth living?
According to GiveWell’s estimates, AMF saves a life (i.e. prevents a premature death) for around $3,500 . Suppose that grants 60 counterfactual years of life. Let’s again use life satisfaction scores as our metric of well-being. Average life satisfaction in Kenya, where AMF operates, is 4.4 out of 10.
Now we run into a problem. Life satisfaction surveys don’t ask people to specify what point on the 0 to 10 scale they would consider equivalent to not being alive. 0 is labelled ‘extremely dissatisfied’ and 10 ‘extremely satisfied’. Intuitively, the mid-point in the scale, 5, would be the neutral point. Yet, if that’s true, then saving lives through AMF would, in fact, be bad: 4.4 (out of 10) is below the neutral point, so AMF are prolonging lives not worth living.
Let’s suppose instead the neutral point is 4. If this is so, saving the child is worth 0.4 life satisfaction points a year for 60 years, thus 24 LSPs (0.4 x 60). Given the $3,500 cost, we can calculate cost-effectiveness as 6.9 LSPs/$1,000. Earlier, I estimated StrongMinds’ cost-effectiveness was 8 LSPs/$1000. If these estimates are correct, then StrongMinds is still more cost-effective, albeit only slightly, than AMF. Of course, we should be cautious about taking these estimates too literally.
The problem here is that these cost-effectiveness numbers are highly dependent on a (so far) arbitrary decision about where the neutral point goes. If someone instead assumes the neutral point was 3 then AMF’s cost-effectiveness would leap to 24.4 LSPs/$1,000 and it would be more cost-effective than StrongMinds, at least on this simplified picture.
I note this approach to comparing life-improving to life-comparing interventions - assessing how much additional life satisfaction is generated - is different to GiveWell’s approach, which involves asking their staff to judge how many years of doubled consumption are morally equivalent to saving a child’s life.
More work is therefore urgently needed to determine where the neutral point is. Two potential methods for doing this would be (1) asking people to state where they think this neutral point is; or (2) using mood reports and finding out at what score on the life satisfaction scale people report net neutral mood.
Should you prioritise mental health?
Mental health vs other life-improving interventions
 Michael Plant, (2016). “Are You Sure You Want To Donate To The Against Malaria Foundation?” Effective Altruism Forum.
 “The Meat-Eater Problem - Effective Altruism Concepts,” accessed 21 September, 2018.
 Hilary Greaves, “Optimum Population Size,” in Oxford Handbook of Population Ethics, ed. Arrhenius, Bykvist, and Campbell (Oxford University Press, n.d.).
 GiveWell, (2018). “2018 GiveWell Cost-Effectiveness Analysis — Version 4.”
 Helliwell, J., Layard, R. and Sachs, J. (2017). World Happiness Report 2017, p28
 Plant, M. (2018). “Life Satisfaction Impact of Treating Mental Health vs Alleviating Poverty.”