This actually occurred quite successfully in the SOMA neighborhood of San Francisco over the past few years. Several thousand units were built, and lo and behol

This actually occurred quite successfully in the SOMA neighborhood of San Francisco over the past few years. Several thousand units were built, and lo and behold rent was flat to downwards depending on the part of SOMA. Many people don't want to live in SOMA though, and the zoning in most of the city doesn't allow for the same kind of rapid, high-density construction. At the same time, Weiner's plan to designate everything as "transit rich" was effectively crazy and DOA. If you're on the Market Street corridor, it makes sense to have denser housing. Being up to a mile away from "transit" in a city that is only 7 miles wide was a poorly reasoned stretch. He sadly threw the baby out with the bathwater, setting back any rational discussion of upzoning near actual transit.