First of all, to Michael and team: Thanks a lot for writing this. I am very happy that this topic is now receiving more attention.
A couple of thoughts on two parts of the manifesto:
1) “The evaluative and experience measures do correlate, suggesting evaluative judgements are, in part if not in whole, determined by how happy people are. “ (OECD 2013, p32-34).
Looking into the source for this claim reveals that the correlation between life satisfaction and positive/negative affect is actually fairly low (r=(-)0.25). Also, this does not tell us much about which determines which (as a matter of causality). This suggests to me that relying only on life satisfaction as a proxy might be potentially misleading if we want to measure happiness as an affective component of SWB. On the other hand, as most studies to date have not measured this component, there does not seem to be a viable alternative (or is anyone aware of other potential proxies?). In any way, (as stated) we will need to be very cautious in interpreting LS outcomes.
2) "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)."
This calculation does not account for potential changes in the happiness of people in Kenya in the future. The WHR (https://s3.amazonaws.com/happiness-report/2018/WHR_web.pdf; p.24) shows that happiness in Kenya has increased by 0.27 points between 2008-2010 and 2015-2017 . This indicates that LS is actually increasing and saving lives might thus do more good than initially calculated. However, I am currently unaware of more data to come up with a reasonable proposal for an alternative calculation. Does anyone know more?