Science informs us that our sense of smell can evoke vivid memories. The phenomenon is sometimes known as the “Proust Effect,” for a scene from Marcel Proust’s novel “Remembrance of Things Past,” when a character’s childhood memories come flooding back, triggered by the scent of a sweet cake called a madeleine.

In cities across the U.S., the housing crisis has reached a breaking point. Rents are skyrocketing, homelessness is rising and working-class neighborhoods are threatened by displacement.

These challenges might feel unprecedented. But they echo a moment more than half a century ago.