It comes down to cost: expensive land, plus expensive permission to build on it. Land in the desirable, job-rich parts of California costs plenty to begin with. Turning that land into buildable, permitted lots adds a lot more. Entitlements, building permits, and the layers of regulatory review that sign off on whether and how you can build all pile cost and time onto a project before a single home goes up. In some California jurisdictions the fees alone can run on the order of $100,000 per home before a shovel hits the dirt. That covers neither materials nor labor; it's the price of permission. When the up-front cost and risk run that high, builders take their capital to states where they can build faster, cheaper, and with less uncertainty. Many have done exactly that. The knock-on effect matters for buyers. So little new supply gets added, especially the entry-level supply that would relieve the most pressure, that the constraint feeds straight back into California's high prices. Tight building keeps supply scarce, and scarce supply in high-demand areas holds prices up. Almost no new construction and expensive housing are two sides of the same coin.