Nice post! I think though that there is an important class of exceptions to scope matching, which I’ll refer to as “well-engineered systems”. Think of for example the “The Wonderful One-Hoss Shay” described in the Oliver Wendell Holmes poem where all of the parts are designed to have exactly the same rate of failure. Real world systems can only approach that ideal, but they can get close enough that their most frequent error modes would fail the scope matching heuristic.
I bring this up in particular because I think that crime rates might fall into that category. Human societies do spend a bunch of resources on minimizing crime, so it isn’t totally implausible that they succeed at keeping the most common crime causes low, low enough that most of the variation in the overall crime rate is driven by localized (in time and space) one-off factors like lead.
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