This is all rings very true, but there's a lemma which might not play well on HN: how much does requiring people to use public transit reduce the birth rate?
Getting 3+ children around town to school, errands, etc in a minivan isn't a trivial job. Dragging around 3 under-six children by bus, or train? That's nearly Herculean.
I would expect the fertility hit to large families from the _lack_ of cars to be far, far greater than the hit from requiring larger cars. This also aligns with the (traditional) higher US fertility rate, where the US has been traditionally (large) car focused, whereas small cars and mass transit dominated in Europe.
Getting 3+ children around town to school, errands, etc in a minivan isn't a trivial job. Dragging around 3 under-six children by bus, or train? That's nearly Herculean.
I would expect the fertility hit to large families from the _lack_ of cars to be far, far greater than the hit from requiring larger cars. This also aligns with the (traditional) higher US fertility rate, where the US has been traditionally (large) car focused, whereas small cars and mass transit dominated in Europe.