Index design · 2026-10-11 · BestCityToLive Research
The city boundary problem: what a credible comparison must get right
Municipal populations, commuting regions and national averages describe different things. Treating them as interchangeable can change a ranking before the formula even runs.
A city is more than its municipal line
OECD functional urban areas combine a dense city with a surrounding commuting zone. The purpose is to capture an economically connected area that crosses administrative boundaries. This matters when one city’s population refers to its municipality and another’s refers to its metropolitan region: totals and per-person measures may be incomparable.
The Civometra model requires harmonized urban-area geography for scored observations. We retain a separate geography label for contextual research. In Canada, even similarly named police and census metropolitan areas can have different boundaries.
A national average is useful context, not a local measurement
Country-level internet use or life expectancy helps describe the wider setting. It does not establish internet service or healthcare access in a specific neighbourhood. National observations appear in the evidence desk with an explicit scope label and never enter the city-scoring engine.
This is a deliberate limit. Filling a missing local measure with a convenient country average would increase the number of populated cells while hiding the absence of city evidence.
More data is not automatically more comparability
WHO’s air-quality database cautions against using its city records to rank the most polluted cities because monitoring capacity and completeness differ. A future Civometra air-quality input therefore needs a consistent exposure method and coverage review. We do not directly rank those WHO records.
The same principle applies across the model: an indicator needs a clear unit, time window, geography and source. Before accepting it, we ask whether the same measurement could fairly be collected for the other cities in the cohort.
Sources & scope
- OECD — Definition of cities and functional urban areas ↗
- WHO — Ambient air quality database and use limitations ↗
- Statistics Canada — Geographic crime comparisons ↗
Research interpretation by BestCityToLive. Source observations may refer to earlier periods. This note does not constitute an official Civometra Index results release.