In Spain it happens as well. The official city population numbers quoted by most sources are actually the population of the city's municipality. Sometimes munic

In Spain it happens as well. The official city population numbers quoted by most sources are actually the population of the city's municipality. Sometimes municipalities are large, including rural areas and small towns close to the city, while other times they are smaller and leave outside areas that are effectively boroughs of the city (you walk down a street and are in a different municipality, without even going through any non-urban area). Some years ago there was a project to merge municipalities, focusing especially on cases like that, but it failed spectacularly because it required consent from all municipalities involved and the smaller ones never wanted to merge (partly because it's advantageous for them to not pay big city taxes but still use their services, but I suspect mainly because mayors don't want to just give up their position and go find another job). This makes rankings by population rather biased and spawns many endless discussions on whether city X is bigger than its rival city Y (and sometimes it might actually have real-life consequences, say, when the central government comes up with some funds for cities of size greater than some threshold).