cross-posted on the EA Forum
I'm interested in questions of the form, "I have a bit of metadata/structure to the question, but I know very little about the content of the question (or alternatively, I'm too worried about biases/hacks to how I think about the problem or what pieces of information to pay attention to). In those situations, what prior should I start with?"
I'm not sure if there is a more technical term than "low-information prior."
Some examples of what I found useful recently:
1. Laplace's Rule of Succession, for when the underlying mechanism is unknown.
2. Percentage of binary questions that resolves as "yes" on Metaculus. It turns out that of all binary (Yes-No) questions asked on the prediction platform Metaculus, 29% of them resolved yes. This means that even if you know nothing about the content of a Metaculus question, a reasonable starting point for answering a randomly selected binary Metaculus question is 29%.
In both cases, obviously there are reasons to override the prior (for example, you can arbitrarily flip all questions on Metaculus such that your prior is now 71%). However (I claim), having a decent prior is nonetheless useful in practice, even if it's theoretically unprincipled.
I'd be interested in seeing something like 5-10 examples of low-information priors as useful as the rule of succession or the Metaculus binary prior.
Some geography documents referred that in Japan if you are prosecuted for a crime you are found guilty 97% of the time. In the first way of telling about a particular case this works in the opposite way that this distribution tells less than a prosecution in a random country. Then in a second way how this very limited factoid gives reason to suspect that something is very amiss with the system.
The documentary put forth that Japanese hate for the state to be proven wrong and go to inappropriate lengths to avoid such flows of events. It also feels that culture has greater weigth for the gravity of not fitting in, so a lot of the conflict resolving might be done "informally" before it becomes police business. With active witchhunters the official officials only do the most extreme cases or the most excusable gray area usages are being actively hidden if they are otherwise socially desirable.
Probably if one were interested in tweaking the system there would have to be details on who has the authority do what based on what level of proof. And the case that the system is working correctly could have many details to great length to seem okay. And I would guess that true progress would be a very slippery and hard to detect and very resistant to trivial solution attempts. Yet the case that there is something to be found seems pretty strong.
This source gives the conviction rate a range of 83.3% to 97.7% depending on the level of court and the type of charge.