It makes sense that places with high population density and a strong tech / banking industry would have the highest property values, because that's where people desire to go and it's where people with money want to go and in big cities isn't the supply of housing restricted by zoning? All of that results in...what you see. As to how to correct for it and prevent property values from exploding to even more unreasonably high values I'm not quite sure. Maybe restructure zoning laws or implement market caps?