Michael Blanding

American workers are usually a pretty busy bunch, yet their time spent idle costs employers an estimated $100 billion per year, according to a new study from Harvard Business School.

You can see the subtle changes when a neighborhood is on its way up—streets get cleaner, building facades improve, new businesses start moving in. Across an entire city, however, it’s harder to track such changes, to understand in real time which neighborhoods are improving and which may need an extra boost in development.