I would actually suspect parents of a half blood (is there a name for this?) would be the weak link, rather than muggle-born children.
You've got people who have lived their whole lives as muggles, then suddenly they fall in love and get married and find out their spouse is a wizard. They've spent ~20 years in the muggle world and probably have a career of their own. No way they don't ask their spouse to spend a couple hours and let them both live like kings for the rest of their lives. And if they don't even get that much information about their other's life, that's some seriously messed up power dynamics in that household.
Pop quiz: What percentage of Muggles have ever heard the word "arbitrage"?
(Retracted because reply makes sense)
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 81, which should be published later today. The previous thread passed 400 comments as of the time of this writing, so it will pass 500 comments soon after the next chapter is posted, if not before. I suggest refraining from commenting here until chapter 81 is posted; comment in the 12th thread until you read chapter 81. After chapter 81 is posted, I suggest all discussion of previous guesses be kept here, with links to comments in the previous thread.
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.) When posted, chapter 81 should appear here.
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: one, two, three, four, five, six, seven, eight,nine, ten, eleven, twelve.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
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: