Very informally, by the amount of times that new innovations or changes are objected to on roughly Chesterton fence reasons, and they turn out to be ok after all. It seems that our modern societies have a certain flexibility built in that allows them to route around certain problems and take advantages of certain opportunities, in ways that pure "Chesterton fence" thinking doesn't allow.

However, this is very far from a rigorous, quantified argument (though the original argument wasn't either).

That was the same thing that struck me. What's the data for this claim?