Bayesian Mindset

A large part of effective altruism – or life in general —  is accurate decision-making. We have to make sure we put our efforts in the right place, but how do we know?

Bayesian thinking, something you might’ve heard about in economics, is a guide to making decisions based on probabilities and values. Imagine you're deciding whether to buy travel insurance for $10. You figure there's about a 1% chance you'll need it, and if you do, it'll save you a $500 airfare. So, you calculate 1% of $500 and see it's $5, which is less than the insurance cost, so you skip it (Karnovsky). It's not just about saving money though; it's about maximizing what's important to you. This approach, called expected utility maximization (EUM), seems like the best way to make decisions. They say either you do EUM or your decisions are botched somehow. It's hard to always reduce everything down to this, but it’s helpful to aim for it, to set up a standard. This standard essentially reduces the number of debates and disagreements that prevent important decisions from being made. For example, when politicians argue about spending, it's hard to know what they're disagreeing on. One says it's about helping people now, and the other worries about future problems. With Bayesian thinking, they'd have to show their cards: the probabilities of outcomes and how much they value them. Then, we'd see clearly what they're fighting over. It's not just for politicians; it's for us too. Sometimes, we're not even sure why we decide things. We might mix up selfish and helpful motives or confuse our beliefs with wishful thinking. Bayesian thinking says, "Pick your values and stick to them," then you can depend solely on them. 

Bayesian thinking splits disagreements into two parts: probabilities and values. Values are what we care about, like helping people or feeling good. Probabilities are how likely things are to happen. By separating them, we can understand arguments better. Values are simple to judge - either you care about something or you don't. Probabilities are trickier, but they can be judged based on evidence and results. If someone lies about their probabilities, they'll get caught eventually.

So, the idea is to practice Bayesian thinking. Try to untangle probabilities from values. That way, we can communicate better, learn from each other, and hold ourselves accountable for being right or wrong. It's not easy, but it's worth aiming for. In a world full of complex decisions, Bayesian thinking could be a compass, guiding us toward what really matters.

Main reference: https://forum.effectivealtruism.org/posts/Mzc2ZP48KPF45t4bQ/bayesian-mindset#Use_cases__pros_and_cons_of_the_Bayesian_mindset