OK. Maybe I am entirely clueless here, but I just don't see how if you pay official A to keep check on official B how the heck they don't instantly collude into a mafia the very second citizen volunteer vigilance stops keeping watch on them?
Here is one interesting thing. People with radical politics, anarchists, communists, libertarians, suchlike, tend to say precisely that, that yes, they collude. Even "conservative" Chesterton said every aristocracy is a mob with style (or something similar, not accurate quote).
People who are moderates and skeptical should probably think it happens to some extent all the time, but all the difference between the first world and the third is precisely the extent of it: preventing most of that collusion, preventing that one big political-business-criminal mafia "blob" from coming into existence and colonize the top echelons is what is the difference between functional and dysfunctional, improving and deteriorating places.
But instutions like playing one Ivy League windbag to keep check on basically his classmate cannot possibly work in themselves, they collude very easily. There must be some other kind of "trick" there.
Of course it's possible for collusion to take place. So you have to make it hard for collusion to take place, you need failsafes. That's why I didn't just say "you need a guard" I talked about transparency and the legal regime. There are different ways this can work.
You are right that one element is to make sure that affinity networks (like Ivy League classmates or ethnic groupings) don't get to colonize the top echelons. But there's more to it than that. I think you need to look at the specific legal regimes in a bunch of Western countries, see ...
I decided to link to this article, because this seems to be all about what Less Wrong is about: http://www.newyorker.com/magazine/2014/11/10/better-time. Out of interest, does anyone know of a good resource for learning more about the training techniques used in elite athletics?