These are property tax returns. Property tax returns come from property prices. Making a neighborhood nicer raises property values, and thus prices. The arti

These are property tax returns. Property tax returns come from property prices. Making a neighborhood nicer raises property values, and thus prices. The article is making the observation that it's much easier and cheaper to improve bad neighborhoods than rich ones. Painting crosswalks and planting trees is cheap, but rich neighborhoods already have those things.