Is "Mu" a more common last name than "Xi" in China?

Question

Is "Mu", which has a coronavirus variant named after it by the World Health Organization, a more common last name than "Xi", which the WHO has avoided naming a variant after?

Example comments on Reddit:

Mu, which has a variant, is a more common last name in China than Xi.

and

Xi (习) doesn't even show up in a list of top 400 common last names in mainland China compiled in 2013 (where the 400th last name had a percentage of 0.0060%. So, if your last name's percentage is even less than that, I find it hard to argue that it's "common")

Also, Mu (穆) is actually on that list, ranked 188 (0.048%) - while also being a variant name. So, it's a complete garbage lie that they're skipping letters because they happen to match with a common last name; we don't even need to talk about pronunciation.

I bet the person who came up with that excuse has zero clue about what last names are even common in China - because, if they did, probably should have picked a better excuse...

*Though, 习 does show up in some 1987, 1995, and 2006 data of top 400-500 last names (in around ranks 390-400+). But 穆 is still ahead of 习 even in those lists (in ranks 100-200). The only data that shows Xi being a common last name, in the top 100 ranks, is from... the Northern Song dynasty.

The New York Times article How Omicron, the New Covid-19 Variant, Got Its Name cited the World Health Organization as saying

“‘Nu’ is too easily confounded with ‘new,’” Tarik Jasarevic, a W.H.O. spokesman, said on Saturday. “And ‘Xi’ was not used because it is a common last name.”

He added that the agency’s best practices for naming diseases suggest avoiding “causing offense to any cultural, social, national, regional, professional or ethnic groups.”

Related question: Did the WHO name the latest COVID-19 variant Omicron, skipping the names Xi and Nu?

Answer 1

To turn my comments into a semi-reliable answer (meaning I have not much expertise in this): it seems the frequency data is being cited from Wikipedia, but the data is patchy and appears to have been (more) cherry picked Xi-wise in the Reddit comments. Before we delve into data, it's worth noting that one Romanization (like Xi) corresponds to several actual Chinese names in their ideography. Not only is the data patchy regarding the actual Chinese names writing-wise, but it's rather even more difficult to find combined statistics corresponding to the grouping Romanizations. E.g. what Wikipedia says in the two separate surname articles:

Mu:

Surname Mù (穆) It is the 98th name on the Hundred Family Surnames poem. 188th name in 2013 shared by 0.048% of the population or 640,000 people with the province with the most being Guizhou. [...]

Surname Mǔ (母) 344 母 0.010% 13.50 Sichuan.

(It's not immediately clear idea what what the last line means, but it appears copied from a table that we'll discuss a bit later.)

Xi:

[Surname Xi] 奚 It is the 45th name in the Hundred Family Surnames poem.

[Surname Xi] 席 It is the 133rd name in the Hundred Family Surnames poem.

[Surname Xi] 郗 It is 234th in the Hundred Family Surnames poem.

[Surname Xi] 習/习 It is 332nd in the Hundred Family Surnames poem. However it is not among the 400 most common surnames, occupying 0.01% of the Han population. [It's the one used by Xi Jinping.]

Note that the poem data (which from a millennium ago) is probably not ordered in frequency of occurrence, even at the time.

A separate article/table in Wikipedia provides a slightly more complete picture, according to a 2013 survey (by a certain Fuxi Institution), which only has data for the top 400 names though:

Rank	Name	% of pop.	No.（10,000's）	Province with most
188	穆 (Mu)	0.048%	64.00	Guizhou
344	母 (Mu)	0.010%	13.50	Sichuan
213	席 (Xi)	0.036%	48.00	Henan
278	奚 (Xi)	0.017%	23.10	Jiangsu
13	馬/马 (Ma)	1.290%	1720.00	Henan
99	莫 (Mo)	0.180%	233.00	Guangxi
373	茅 (Mao)	0.0076%	10.10	Jiangsu
182	解 (Xie)	0.053%	71.00	Shandong
67	夏 (Xia)	0.320%	426.00	Jiangsu

(The other Xi's like 郗 and 習/习 indeed don't appear in that 2013 top-400 survey list.)

According to this 2013 survey, there were at least 711,000 Xi-Romanized surnamed people (23.1 奚 + 48 席 = 71.1 Xi); and at least 775,000 Mu-Romanized surnamed people (13.5 母 + 64 穆 = 77.5 Mo). So the numbers are bit closer than Reddit claims, although Mu does have slight edge in this comparison (which does exclude the >400 ranked names though, so it's not a complete data set.)

If you actually count/include the close enough (IMHO) Romanization-wise Xie (解), there are some additional 710,000 thousands of these alone; never mind the Xia's (夏), of which there are some 4.26 million, which would make the Xi+Xie+Xia twice as numerous than the Mu's even when combined with Mo's (莫) -- as there only some 2.33 million Mo's. (Strikingly, there's not that many Mao's 茅; that ranks at position 373.) On the other hand, there's the "hidden dragon" Ma (馬/马) with 17.2 million, far outranking the rest of those I've mentioned.

It's a slippery slope at this point, I guess. One could even bother with the consonant-ending Meng (孟), Xing (邢), Xiong (熊), and Xiang (向 and 相) all fairly common (孟 ranks 73 with 3.84 million, 熊 ranks 72 with 3.94 million, 邢 at 111 with 1.92 million, 向 is at 102 with 2.26 million and 相 at 320) etc.

Rank	Name	% of pop.	No.（10,000's）	Province with most
73	孟 (Meng)	0.290%	383.00	Shandong
72	熊 (Xiong)	0.290%	384.00	Jiangxi
111	邢 (Xing)	0.140%	192.00	Shandong
102	向 (Xiang)	0.170%	226.00	Hunan
320	相 (Xiang)	0.012%	16.20	Shandong

Note that Mo (莫) is sometimes Romanized as Mok (esp. in Cantonese--apparently due to different pronunciation in the latter), so the issue with consonants-ending is not that straightforward.

Adding all the Xi-prefixed names certainly beats the Mu's, but probably not the Ma's.

And I'm totally torn about Xu's (許/许 and 徐). In which (larger) bin should these go in the Xi vs Mu debate?

Rank	Name	% of pop.	No.（10,000's）	Province with most
11	徐 (Xu)	1.450%	1930.00	Jiangsu
26	許/许 (Xu)	0.660%	881.00	Guangdong

And if you're asking my hunch, it's probably the case that (regardless of actual frequency in China) the average Westerner doesn't know (can't indicate) any individual named Mu (or even the far more common Ma or Xu), but for Xi there's the obvious presidential designator.