Every index has an implied reader. Read the methodology of any liveability ranking closely and a person emerges: salaried, mobile, childless, recently arrived, likely to leave.
That person is real. They are not most people in the city being ranked.
The metric nobody publishes
Ask residents what makes somewhere liveable and the answers are strikingly consistent and almost entirely absent from the indices: can I stay here in ten years, is it quiet at night, is anything I need within a walk.
Liveability, as residents describe it, is mostly a question about permanence. The rankings measure arrival.
None of these are hard to measure. They are hard to compare across borders, which is a different problem — and it is the index’s problem, not the city’s.