Yes, but a lot of people, for various reasons, either believe that econ 101 arguments don't apply in this situation or that even if they do, the effects of buil

Yes, but a lot of people, for various reasons, either believe that econ 101 arguments don't apply in this situation or that even if they do, the effects of building market rate housing are still undesirable. Their actual stated arguments tend to be delivered in unconvincing ways, but Julia Galef (who I gather does believe in the econ 101 take) took a stab at steelmanning that side in https://juliagalef.com/2017/07/13/should-we-build-lots-more-housing-in-san-francisco-three-reasons-people-disagree/ https://juliagalef.com/2017/07/13/should-we-build-lots-more-..., and it's definitely worth a read. What I'd add to her points is a fourth, that while some people believe that either overall affordability or total number of below market rate units are the right metrics to measure success by, some people care more about the percentage of affordable units than the number. An extreme version of the argument says that having 100 affordable units out of 200 total is better than having 200 affordable units out of 1000 total, because the second scenario will mean a strong demographic shift in the neighborhood (a "whitening"), not to mention an increase in density that will change the feel of the area. This is not an economic argument, but one about values, so it's not going to be resolved by numbers.