No, they're not. It's the other way around, in fact. Suburbs subsidize cities (on average, again).

The dense city cores produce most of the _corporate_ income tax, because that's where the companies are headquartered. But most of _personal_ income tax comes from suburbs. This is only now getting close to flipping around.

Cities also have YUUUUGE expenses that simply don't happen in sparse areas. E.g. infrastructure like water or sewer is wildly expensive in cities because of the planning overhead. Case in point: San Francisco spent almost half a billion rebuilding a few blocks of road.

Cities also require EXPENSIVE public transit. One ride on a bus/subway in the US costs around $20. I'm talking about the true cost (number of trips / total expenses), not the farebox cost. And with capex it's almost incalculable, with crazy numbers like $50 per ride for Seattle.

The TLDR; version:

1. Infrastructure in suburbs might end up being a bit more expensive on a per-capita basis. Or it might not, depending on the way you do accounting.

2. In any case, this difference is not at all significant.

3. Suburbs are _not_ subsidized, and in fact generate most of the wealth in the US.