Also, America, no wonder your commute is long, theres a 10 lane highway surrounded by a bunch of single-family homes. If you want to put more people into the same space, what you usually do is go up in height.
A certain niceness of a house in a certain market will tend to sell/rent for $X per month, no matter how you arrive at $X. So if property taxes are high, it tends to reduce the actual price of the house since people don't just pay a mortgage, but rather have to pay everything associated with the house; mortgage, insurance, taxes, etc.
This is a similar phenomena to the low interest rate, high property price that we've witnessed over the last decade or so in the US. At 4% a 200k house costs about $1k/mo once you roll in some kind of property tax and PMI. At 8% $1k/mo buys you less than 100k of house again assuming the same property tax and PMI.
So what happens in other locations is that demand for locations starts going up, housing prices go up, taxes go up and people who can't pay those taxes get displaced. Developers buy those houses, raze them in favor of apartment complexes and eventually you get density.
If people can stay in their single family 1.5 or 2 million dollar homes and pay property taxes on the 30k they bought it for 30 years ago density won't happen because those are the people that vote and they'll keep voting for municipality limits on building to "keep the character of the neighborhood".
No, it restricts increases in the basis value to which the tax rate is applied to a maximum of the value after purchase (or other qualifying event) + 2% per annum.
> unlike most places where you pay property tax on the current value.
A number of other states have Prop 13 like limits to the annual increase in tax basis value, and some others do full market valuation but split the increases over a several year period so that the tax basis value lags the increase, and other places just have fairly infrequent reassessment except at purchase (which, in effect, also causes tax basis value to, on average, trail behind increases.)
Because of California's lenient qualifications, someone who bought that $30k house can move to North Carolina and collect massive rent checks without seeing their property taxes jump to reflect reality. The owners of apartment complexes have a vested interest in keeping their properties as they are, since a major renovation or addition would trigger a revaluation. Same for owners of office and retail space who aren't big enough to cut tax deals with the various levels of municipal government.
Furthermore, property taxes normally force some people out of their homes; this isn't as bad as it sounds - in SF at least, they would get a hefty windfall. On average, the property would be used more efficiently by the new owner.
NIMBYism is the biggest problem in SF. Every year, 20K people or so move into the city while we only build enough housing for roughly one tenth of them. Housing has increased by ~10-15% a year for the past decade or so.