Not an economist either, but your analogy to software made me think. If you had a piece of software that ran for 100 years and only crashed every few decades, p

Not an economist either, but your analogy to software made me think. If you had a piece of software that ran for 100 years and only crashed every few decades, presumably the people maintaining the code would have retired and handed it off to other people at least 5 or 6 times. The maintainers still in place with a memory of the last crash might have some idea how to avoid another one, but as the ranks get filled by people who don't remember, they're more prone to careless errors, or think they can execute tweaks or drive the system harder than it can be driven. Or they don't fully understand something and think it can be removed for the sake of expedience, without realizing why it was there. So rather than a problem in the code, it may be a problem in the nature of maintaining and updating it.