Of course this system can work only where just a fraction of the new housing is sold "below market." Moreover, the market price of housing is raised so far above what it was by building restrictions that even "below market" prices for condominiums in Palo Alto can run to $300,000 or $400,000.
This is hardly "affordable housing" for people on modest incomes. Only 7 percent of Palo Alto's police, for example, live in Palo Alto-- probably older cops who bought their homes long ago.
But none of that matters politically. What matters is that people in Palo Alto can feel good about themselves, by being for both "open space" and "affordable housing." Happy voters are what get politicians re-elected.
The big political crusade today is for "affordable" medical care through the government. No one believes that government is just going to be more efficient, and thereby have lower costs that will be reflected in lower prices for medications and medical treatment.
It might seem as if adding the costs of government bureaucracies to the costs of medications and medical treatment would make it impossible for the total costs to go down. But again, the impossible is no problem in politics.
Many countries around the world already have government-run medical care. People who get sick in these countries usually wait much longer to get treatment, including months on waiting lists for surgery, often paying in pain or debilitation, rather than money.
High-tech medical devices like MRIs are also far less common in these countries than in the United States. With medical care as with anything else, you can always get poorer quality at a lower price, though that is no bargain, especially when you are sick.
What you may have in mind are lower prices with no reduction in quality. While that may be impossible, don't expect that fact to stop politicians from offering it, even if they can't deliver.