#37 - GiveWell picks top charities by estimating the unknowable. James Snowden on how they do it.

What’s the value of preventing the death of a 5-year-old child, compared to a 20-year-old, or an 80-year-old?

The global health community has generally regarded the value as proportional to the number of health-adjusted life-years the person has remaining - but GiveWell, one of the world’s foremost charity evaluators, no longer uses that approach.

They found that contrary to the years-remaining’ method, many of their staff actually value preventing the death of an adult more than preventing the death of a young child. However there’s plenty of disagreement: the team’s estimates of the relative value span a four-fold range.

As James Snowden - a research consultant at GiveWell - explains in this episode, there’s no way around making these controversial judgement calls based on limited information. If you try to ignore a question like this, you just implicitly take an unreflective stand on it instead. And for each charity they look into there’s 1 or 2 dozen of these highly uncertain parameters they need to estimate.

GiveWell has been trying to find better ways to make these decisions since its inception in 2007. Lives hang in the balance, so they want their staff to say what they really believe and bring their private knowledge to the table, rather than just defer to a imaginary consensus.

Their strategy is a massive spreadsheet that lists dozens of things they need to estimate, and asking every staff member to give a figure and justification. Then once a year, the GiveWell team get together and try to identify what they really disagree about and think through what evidence it would take to change their minds.

Full transcript, summary of the conversation and links to learn more.

Often the people who have the greatest familiarity with a particular intervention are the ones who drive the decision, as others defer to them. But the group can also end up with very different figures, based on different prior beliefs about moral issues and how the world works. In that case then use the median of everyone’s best guess to make their key decisions.

In making his estimate of the relative badness of dying at different ages, James specifically considered two factors: how many years of life do you lose, and how much interest do you have in those future years? Currently, James believes that the worst time for a person to die is around 8 years of age.

We discuss his experiences with such calculations, as well as a range of other topics:

* Why GiveWell’s recommendations have changed more than it looks.
* What are the biggest research priorities for GiveWell at the moment?
* How do you take into account the long-term knock-on effects from interventions?
* If GiveWell's advice were going to end up being very different in a couple years' time, how might that happen?
* Are there any charities that James thinks are really cost-effective which GiveWell hasn't funded yet?
* How does domestic government spending in the developing world compare to effective charities?
* What are the main challenges with policy related interventions?
* How much time do you spend discovering new interventions?

Get this episode by subscribing to our podcast on the world’s most pressing problems and how to solve them: search for '80,000 Hours' in your podcasting app.

The 80,000 Hours Podcast is produced by Keiran Harris.