This might be an explanation of why the Dementors seem to be concentrated at Azkaban... fail to cast a Patronus and something produces a Dementor there. Although I don't think this is right because it seems too complicated, and I seem to recall something saying that wizards gathered/herded the Dementors to their nest in Azkaban.
There's also the fact that Azkaban is a small isolated island in the middle of a storm-swept sea. If by some accident of magical geography it happened to be the place where all Dementors naturally spawned, the probability of someone coming across the island AND discovering the Dementors AND living to tell the tale to the government is pretty low.
But if all the Dementors are rigidly controlled by the government, you might expect them to notice new Dementors being created outside their control even if it isn't obvious what is creating them.
Has it been established that Azkaban accounts for all Dementors? I can't remember any conclusive evidence in either direction.
My inference is based on the complaints Dumbledore makes about getting permission to bring a Dementor to Hogwarts and then having to explain its disappearance. You're right, though, it implies that the Ministry makes a firm accounting of the Dementors in Azkaban or otherwise under its control, but it doesn't really say anything about all Dementors everywhere.
Again the ghost of that statement about the wizards herding them all to Azkaban rises up... I don't remember if that statement claimed ALL Dementors had been moved there or if it was just all the ones in Britain. I don't even remember if that was a statement from canon or HPMoR or how reliable the speaker is.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 96. The previous thread is at almost 300 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, .
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: