For similar cars and drivers, automobile insurance for collision damage has always cost more in Greatport than in Fairmont. Police studies, however, show that cars owned by Greatport residents are, on average, slightly less likely to be involved in a collision than cars in Fairmont. Clearly, ttherefore, insurance companies are making a greater profit on collision-damage insurance in Greatport than in Fairmont.
Repairing typical collision damage does not cost more in Greatport than in Fairmont is an assumption on which the argument depends.