EA - A can of worms: the non-significant effect of deworming on happiness in the KLPS by Samuel Dupret

Link to original articleWelcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: A can of worms: the non-significant effect of deworming on happiness in the KLPS, published by Samuel Dupret on December 21, 2022 on The Effective Altruism Forum.SummaryMass deworming, where many people are provided drugs to treat parasitic worms, has long been considered a highly cost-effective intervention to improve lives in low-income countries. GiveWell directed over $163 million to deworming charities since 2010. Nevertheless, there are long-running debates about its impact and cost-effectiveness. In this report, we summarise the debate about the efficacy of deworming, present the first analysis of deworming in terms of subjective wellbeing (SWB), and compare the cost-effectiveness of deworming to StrongMinds (our current top recommended charity).Analysing SWB data from the Kenyan Life Panel Survey (KLPS; Hamory et al., 2021), we find that deworming has a small, statistically non-significant effect on long-term happiness that seems (surprisingly) to become negative over time (see Figure 1). We conclude that the effect of deworming in the KLPS is either non-existent or too small to estimate with certainty. Typically, an academic analysis could stop here and not recommend deworming. However, the non-significant effects of deworming could be cost-effective in practice because it is extremely cheap to deliver. Because the effect of deworming is small and becomes negative over time, our best guess finds that the overall cost-effectiveness of deworming is negative. Even under more generous assumptions (but still plausible according to this data), deworming is less cost-effective than StrongMinds. Therefore, we do not recommend any deworming charities at this time.To overturn this conclusion, proponents of deworming would either need to (1) appeal to different SWB data (we’re not aware of any) or (2) appeal to a non-SWB method of comparison which concludes that deworming is more cost-effective than StrongMinds.Figure 1: Differences in happiness between treatment and control groups over time1. Background and literatureIn this section, we present the motivation for this analysis, the work by GiveWell that preceded this, and the broader literature on deworming. We then present the details and context of the dataset we use for this analysis – the Kenyan Life Panel Survey (KLPS).1.1 Our motivation for this analysisThe Happier Lives Institute evaluates charities and interventions in terms of subjective wellbeing (SWB) - how people think and feel about their lives. We believe that wellbeing is what ultimately matters and we take self-reports of SWB to be the best indicator of how much good an intervention does. If deworming improves people’s lives, those treated for deworming should report greater SWB than those who aren’t. SWB should capture and integrate the overall benefits from all of the instrumental goods provided by an intervention. For example, if deworming makes people richer, and this makes them happier, they will report higher SWB (the same is true for improvements to health or education). Although we are not the first to use SWB as an outcome for decision-making (e.g., UK Treasury, Frijters et al., 2020, Birkjaer et al., 2020, Layard & Oparina, 2021), we are the first to use it to compare the impact of charities.See McGuire et al. (2022b) for more detail about why we prefer the SWB approach to evaluate charities.To determine whether the SWB approach changes which interventions we find the most cost-effective, we have been re-evaluating the charity recommendations of GiveWell (a prominent charity evaluator that recommends charities based on their mortality and economic impacts). For a review of our recent research, see this post. We present our findings in wellbeing-adjusted years (WELLBYs), where 1 WELLBY is the equivalent of a 1-point change on a 0-10...