SAN FRANCISCO — Many San Francisco renters I met while reporting an article on affordable housing lotteries had responded to the region’s housing crisis by putting up with great discomfort: They crammed in with family; they split apartments with strangers. Some even lived out of their cars.

Why, lots of readers wanted to know, didn’t they simply move away instead?

Many have. High-cost California has long been losing population to domestic migration, particularly its poorer residents (who head to cheaper places like Arizona, Nevada and Texas).