People want a place of their own

BY 2020 California, already the most populous American state, is expected to be the home of over 45m people, about 11m more than it has now. To be sure, the Golden State covers a lot of space; only Alaska and Texas are larger. But much of that space consists of mountains and desert, and not all of the other parts can always be sure that they will have enough water. This limits the amount of land where people can confidently build their homes. The state's three most heavily populated areas—the Los Angeles basin, greater San Diego and the San Francisco Bay Area—are already starting to burst at the seams. The only region left that can realistically hope to take in large numbers of extra people is the Central Valley, which runs down the middle of the state like a depression left by Zeus's forearm.