- This thread has run its course. You will find newer threads in the discussion section.
Another discussion thread - the fourth - has reached the (arbitrary?) 500 comments threshold, so it's time for a new thread for Eliezer Yudkowsky's widely-praised Harry Potter fanfic.
Most of the paratext and fan-made resources are listed on Mr. LessWrong's author page. There is also AdeleneDawner's collection of most of the previously-published Author's Notes.
Older threads: one, two, three, four. By tag.
Newer threads are in the Discussion section, starting from Part 6.
Spoiler policy as suggested by Unnamed and approved by Eliezer, me, and at least three other upmodders:
You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it's fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that "Eliezer said X is true" unless you use rot13.
It would also be quite sensible and welcome to continue the practice of declaring at the top of your post which chapters you are about to discuss, especially for newly-published ones, so that people who haven't yet seen them can stop reading in time.
(nods) This sort of thing is worth thinking about cautiously before supporting, even in theory. A few other points worth considering in a more detailed analysis:
Beliefs vs. actuality
It's not the actual probability of getting caught that matters for deterrence, it's the potential criminal's belief about that probability.
That is, if I only have a 1% chance of being caught but I believe I have a 99% chance of getting caught, I'm easier to deter. Conversely, if I have a 15% chance of getting caught but believe I have a 0.0001% chance of getting caught, I'm difficult to deter (at least, using the kind of deterrence you are talking about).
Similar things are true about EB and SP -- what matters is not the actual expected benefit or cost, but rather my beliefs about that expected benefit/cost.
Magnitude vs. valuation
People's valuations of a probability of a cost or benefit don't scale linearly with the magnitude of either the cost/benefit or the probability.
Which means that even if (1/p-1)×EB < SP is a manageable inequality for crimes with moderate risks and benefits, SP might nevertheless balloon up when p gets small enough and/or EB gets large enough to cross inflection points.
So the threat of a lifetime of psychological torture might not be sufficiently unpleasant to deter certain crimes. Indeed, it might be that for certain crimes you just aren't capable of causing enough suffering to deter them, no matter how hard you try.
Knock-on effects
Official policies about criminal justice don't just influence potential criminals; they influence your entire culture. They affect the thinking of the people who implement those policies, and the people whose loved ones are affected by them (including those who believe their loved ones are innocent), and of their friends and colleagues.
The more extreme your SP, the larger and more widespread the knock-on effects are going to be.
Addendum
For my own part I think Azkaban, and the whole theory of criminal justice that creates places like Azkaban, is deeply flawed and does more harm than good. I could use stronger terms like "evil," I think, with some justice.
Also, I think the endpoint of the kind of reasoning illustrated above is in practice the conclusion that our best bet is to instill in everyone an unquestioned belief in a Hell where people suffer eternal torment, and unquestioning faith in an infallible Judge who sends criminals to Hell. After all, that maximizes perceived SP and perceived p, right?
Unfortunately, the knock-on effects are... problematic.
There are better approaches.
Such as, ...