Provide easy cleanup of census:population

[1ec5]

census:population tags were originally added to place features across the U.S. as part of the 2009 GNIS import, with 2006 population estimates, and some were later updated to Census 2010 figures. Some additional census:population tags were added manually later for completeness. However, it was never really used outside of that context. population is the approved and more common tag for indicating a place’s population. In many cases, mappers have updated population tags to more current values than census:population because only population has a field in editors like iD.

iD should issue a warning when census:population is present but not population (or the two tags have the same population) and offer to upgrade from census:population to population. If both tags are present, as is often the case, then iD should warn but probably hide the suggested fix, because population may be more up-to-date than census:population. Maybe there could instead be a suggestion to look up the most current figure just to be sure.

This change would go nicely with #6672: a tag like census:population=1388;2006 would be upgraded to population=1388 population:date=2006 source:population=United States Census Bureau. (There are just a handful of census:population-tagged features outside the U.S.) Increased usage of population:date will allow us to confidently update population figures after Census 2020 comes out without affecting more recent estimates that mappers manually put in.

[bhousel]

I feel like rather than introducing more code to handle these tags, could we encourage people to use wikidata for this instead?

[1ec5]

population is basically a renderer convenience for determining label size and collision. If not for how common it is for CartoCSS-based renderers to use this tag, I’d be all for ignoring it. 🤷‍♂ Anyways, the most important thing is to encourage any population figure to be paired with a date (#6672); census:population is a more cosmetic issue.

[Nakaner]

Any serious map style rendering towns and cities takes the population into account. Or how can one determine the importance of a place node?

I think that discussion to deprecate a tag should take place on the Tagging mailing list and not be introduced by the developers of a single editor without any discussion with the community.

[bhousel]

ok, let's not do this

[tyrasd]

This was brought up again in openstreetmap/id-tagging-schema#261.

Can we perhaps just rephrase this? Instead of "deprecating" anything, the core of this proposal – as I understood it – was rather to provide users an easy way to upgrade the nonstandard census:population tag to a approved and thus more usable tagging scheme (i.e. population + population:date + source:population tag combination). The wiki calls this a "Cleanup".

[danieldegroot2]

Ref https://community.openstreetmap.org/t/cleanup-of-old-imported-key-census-population-in-the-united-states/109016