The merge targets are all quite small. AFAICS, the biggest category after the merge will be Category:2013 establishments in the United Arab Emirates , which will grow from 14 to 18 articles ... and most of the merge targets will still have less than ten articles.
Abu Dhabi is a city with a current population of about 2 million. In the 19th and 20th centuries it was a de facto part of the British Empire, as one of the Trucial States. The Trucial States became independent in 1971 as the United Arab Emirates, whose 2013 population was 9.2 million. Wikipedia's coverage of events there is limited, so subdividing the chronology categories by city makes lots of small categories which impede navigation. We don't have by-year categories for any except the very largest cities, and establishment-by-year categories for cities have repeatedly been deleted (see e.g. 2012: London, 2019: Philadelphia & Pittsburgh).
In this case, every single "Category:YYYY in Abu Dhabi" or "Category:YYY0s in Abu Dhabi" is functioning solely as a container category for the corresponding establishment category, and will become empty if the establishment categories are merged. --BrownHairedGirl(talk) • (contribs) 14:45, 30 March 2019 (UTC)[reply]
@Laurel Lodged: For the record, we did not have both of those; one was a redirect to the other. Thanks for the reminder, as that decade was inconsistent with the rest of the hierarchy; I have now revised the close at Wikipedia:Categories_for_discussion/Log/2017_August_26#Category:1908_establishments_in_Poland, and reversed the redirects. As you evidently feel strongly about ahistorical categories in Poland, please make a proposal somewhere with a list of historical territories and dates for which chronology categories might be useful, in order to seek consensus at an RFC. – FayenaticLondon10:00, 2 April 2019 (UTC)[reply]
Not so, @Nyttend backup/Nyttend. First, these categories are named for the city, not the Emirate, so this is a Pittsburgh equivalent. Secondly, the number of articles in scope is way way smaller than for Pennsylvania. Just look at the size of these categories, and of the merge targets: the biggest category after the merge will be Category:2013 establishments in the United Arab Emirates, which will grow from 14 to 18 articles. That is too small a set to split up.
The point is that the nomination, and the support votes, rely on a false impression of the situation (not accusing you of bad faith, just of a misunderstanding). See the airport comment below for proof. Imagine that "Establishments in Quebec by year" were small, and someone nominated it for deletion with the above rationale. It would be a thoroughgoing bad idea to delete a provincial category tree merely because a few people believed that the City of Quebec was too small to warrant its own establishments-by-year category. It's fine if people conclude that a country's primary subdivisions are too small to warrant their own categories; I'd heartily support such a nomination if we had an "Establishments in Yaren District by year" category, for example, and were the nomination and the support votes saying "we don't need separate categories for each emirate", I wouldn't have come in at all. I just don't want to see this category tree abolished because of a misunderstanding. Nyttend backup (talk) 22:49, 2 April 2019 (UTC)[reply]
I'm neutral on the proposal; although the categories are fairly small, they still strike me as viable and marginally useful. Disambiguating these categories to "establishments in the Emirate of Abu Dhabi" has some attraction for me, although I would favour a discussion to rename the main article, after which city-related topics would belong in "Category:Abu Dhabi (city)", and the concisely-named nominated categories could stay put. – FayenaticLondon11:38, 2 April 2019 (UTC)[reply]
Nominator's rationale: Only one article. No real reason to expect more. Though its a significant issue it doesnt really generate articles. Rathfelder (talk) 09:27, 30 March 2019 (UTC)[reply]
Nominator's rationale: merge/delete per WP:OVERLAPCAT, Karlskoga Municipality has 30.000 inhabitants, of which the city of Karlskoga has 27.000 inhabitants; and no villages are mentioned in the municipality article. Buildings, people and populated places of the municipality coincide with those of the city. In option A: keep the parent categories of both (by city and by municipality) for the merged category. Marcocapelle (talk) 09:15, 30 March 2019 (UTC)[reply]
Nominator's rationale:delete, redundant container category with only one subcategory. There is no need to merge, the subcategory is already in appropriate trees. Marcocapelle (talk) 09:14, 30 March 2019 (UTC)[reply]
