Previously in series:  Rationality: Common Interest of Many Causes

When you consider that our grouping instincts are optimized for 50-person hunter-gatherer bands where everyone knows everyone else, it begins to seem miraculous that modern-day large institutions survive at all.

Well—there are governments with specialized militaries and police, which can extract taxes.  That's a non-ancestral idiom which dates back to the invention of sedentary agriculture and extractible surpluses; humanity is still struggling to deal with it.

There are corporations in which the flow of money is controlled by centralized management, a non-ancestral idiom dating back to the invention of large-scale trade and professional specialization.

And in a world with large populations and close contact, memes evolve far more virulent than the average case of the ancestral environment; memes that wield threats of damnation, promises of heaven, and professional priest classes to transmit them.

But by and large, the answer to the question "How do large institutions survive?" is "They don't!"  The vast majority of large modern-day institutions—some of them extremely vital to the functioning of our complex civilization—simply fail to exist in the first place.

I first realized this as a result of grasping how Science gets funded: namely, not by individual donations.