User:Visviva/Dumpster dive

Data on user and article stratification over time, gleaned from the 2022-07-01 stub-meta-history dump of EN wiki.

General numbers

As of the 2022-07-01 stub-meta-history dump:

• Total pages in mainspace: 16666393
• Total users who have contributed at least one non-deleted revision of a page currently in mainspace: 8783518
• Total edits associated with a mainspace page: 722794550
• Total edits to a mainspace page that are associated with a user: 722772635
• Difference (revisions with attribution removed): 21915 (0.003%)

General annual stats

Mainspace only. Excludes bots. Excludes redirects from page count but not from edit count.

Basic stats by calendar year

	Users editing	IPs editing	Pages edited	Redirects edited	User user-page-months	IP user-page-months	User edits	IP edits
2001	1030	0	16978	4014	41942	0	60063	0
2002	1966	16719	94827	25016	246124	76337	350699	112424
2003	8370	59245	140200	64335	613261	183868	974004	278521
2004	37611	283366	397122	228745	2505890	750262	3896678	1159237
2005	148756	1228808	781322	479689	5973071	3090879	9785081	5069111
2006	630074	3387078	1344460	881178	14135037	7947191	25470891	13089251
2007	943270	5001864	1816777	927456	16704193	10607947	30968390	17149981
2008	894634	5039842	2216398	884882	16230635	10067050	29698093	16166731
2009	864149	4650723	2526614	827129	15439551	9147470	28343089	14739273
2010	804968	4378615	2705234	738706	14718878	8497908	26904279	13705928
2011	808259	3698374	2830528	678752	13560671	7088552	25165253	11381104
2012	714093	3395254	3032412	712226	13594185	6535885	24787710	10606703
2013	713666	3115733	3068502	651053	13095303	5998229	23904628	9767365
2014	772545	2613881	3174919	620310	12544149	5248935	23151748	8678007
2015	743490	2797009	3369813	676210	13550707	5590961	25206383	9474953
2016	701861	2976090	3652241	690914	14474956	5838372	26209753	9772962
2017	716793	2919222	3670051	957042	14583807	5651626	26787421	9382811
2018	715240	2887622	3982402	706172	15269394	5463227	27342221	8932214
2019	712830	2892729	3945903	619308	15012268	5423885	27307812	8839292
2020	723696	2923310	4383098	630292	16818593	5283565	30382208	8669883
2021	667693	2805778	4423475	752503	17040539	5190295	30952958	8565447
2022	376831	1261679	3372516	354829	8780589	2342456	15443283	3863418

User classes

By first-year edits

Cf. m:Research:Editor classes (which uses all-namespace edits). Does not currently exclude bots. Note that 2021 and 2022 will be substantially incomplete (since 12 months from first edit will not be up until December 2022 for some 2021 starters, and not until December 2023 for some 2022 starters).

EN Wikipedians who made a total of n edits to pages that are currently in mainspace in the 12 months following their first mainspace edit, by calendar year of first mainspace edit

Year	1-9 edits	10-99 edits	100-999 edits	1,000-9,999 edits	10,000+ edits
2001	638	262	108	21	1
2002	862	541	239	98	6
2003	4012	2438	837	244	15
2004	18779	10974	3288	876	47
2005	81921	37028	9446	2167	90
2006	419673	119473	17932	2887	136
2007	615165	117128	11870	1620	75
2008	549136	93138	8932	1199	78
2009	515956	83819	7904	951	39
2010	467135	72950	6397	732	40
2011	469750	71285	6119	597	27
2012	398055	61711	5561	567	32
2013	404025	58992	5207	521	21
2014	474520	62189	5338	522	19
2015	447422	59536	5268	502	24
2016	412834	53837	4853	493	28
2017	422156	54903	5225	538	23
2018	411455	51961	4911	544	25
2019	402849	51623	4709	527	19
2020	403141	54231	6206	812	42
2021	359627	48528	5731	655	27
2022	172752	19372	1670	94	4

2021 edits by first-year edits

Excludes editors joining during or after 2021. See results for other calendar years.

2021 mainspace editors and edits by first-year edit class

	0 edits in 2021	1-9 edits in 2021	10-99 edits in 2021	100-999 edits in 2021	1000-9999 edits in 2021	>10000 edits in 2021
1-9 edits in first twelve months	6803879 users making 0 edits	104437 users making 246702 edits	9823 users making 241260 edits	1101 users making 320931 edits	227 users making 612468 edits	17 users making 515636 edits
10-99 edits in first twelve months	1015159 users making 0 edits	67421 users making 222303 edits	30589 users making 847559 edits	4008 users making 1131624 edits	767 users making 2084765 edits	75 users making 1808294 edits
100-999 edits in first twelve months	92432 users making 0 edits	10251 users making 35925 edits	9696 users making 375262 edits	6689 users making 2106689 edits	1210 users making 3123022 edits	72 users making 1611375 edits
1000-9999 edits in first twelve months	9917 users making 0 edits	1346 users making 4893 edits	1579 users making 61548 edits	1704 users making 708459 edits	1735 users making 5307778 edits	137 users making 3322450 edits
>10000 edits in first twelve months	465 users making 0 edits	25 users making 63 edits	39 users making 1565 edits	55 users making 25170 edits	108 users making 422066 edits	95 users making 14477369 edits

By calendar-year edits

Excludes bots. Counts edits to pages currently in mainspace only. IP edits not included in percentages.

Number of registered users who made n extant mainspace edits in each calendar year

Year	1-9 edits	10-99 edits	100-999 edits	1,000-9,999 edits	10,000+ edits	Percent of all registered users who edited	Percent of all edits by registered users
2001	712 users making 1,737 edits	231 users making 7,504 edits	80 users making 25,659 edits	6 users making 7,178 edits	1 users making 17,985 edits	69.1 22.4 7.8 0.6 0.1	2.9 12.5 42.7 12.0 29.9
2002	1,099 users making 3,420 edits	567 users making 18,306 edits	225 users making 73,009 edits	72 users making 189,605 edits	3 users making 66,359 edits	55.9 28.8 11.4 3.7 0.15	1.0 5.2 20.8 54.1 18.9
2003	5,123 users making 15,557 edits	2,278 users making 70,530 edits	759 users making 251,240 edits	203 users making 541,206 edits	7 users making 95,471 edits	61.2 27.2 9.1 2.4 0.08	1.6 7.2 25.8 55.6 9.8
2004	24,247 users making 73,647 edits	9,735 users making 298,831 edits	2,846 users making 900,517 edits	742 users making 1,986,752 edits	41 users making 636,931 edits	64.5 25.9 7.6 2.0 0.11	1.9 7.7 23.1 51.0 16.3
2005	105,299 users making 302,441 edits	33,308 users making 982,479 edits	8,208 users making 2,508,261 edits	1,868 users making 4,899,268 edits	73 users making 1,092,632 edits	70.8 22.4 5.5 1.3 0.05	3.1 10.0 25.6 50.1 11.2
2006	489,102 users making 1,346,667 edits	114,389 users making 3,180,812 edits	21,925 users making 6,573,454 edits	4,473 users making 11,468,829 edits	185 users making 2,901,129 edits	77.6 18.2 3.5 0.7 0.03	5.3 12.5 25.8 45.0 11.4
2007	760,679 users making 2,062,123 edits	151,941 users making 4,061,977 edits	25,222 users making 7,474,362 edits	5,205 users making 13,689,563 edits	223 users making 3,680,365 edits	80.6 16.1 2.7 0.6 0.02	6.7 13.1 24.1 44.2 11.9
2008	732,358 users making 1,944,517 edits	135,927 users making 3,610,477 edits	21,349 users making 6,352,150 edits	4,721 users making 12,682,818 edits	279 users making 5,108,131 edits	81.9 15.2 2.4 0.5 0.03	6.5 12.2 21.4 42.7 17.2
2009	710,794 users making 1,851,915 edits	128,672 users making 3,430,016 edits	20,069 users making 5,939,928 edits	4,346 users making 11,698,674 edits	268 users making 5,422,556 edits	82.3 14.9 2.3 0.5 0.03	6.5 12.1 21.0 41.3 19.1
2010	664,656 users making 1,713,515 edits	117,970 users making 3,144,345 edits	18,060 users making 5,342,525 edits	4,011 users making 10,889,394 edits	271 users making 5,814,500 edits	82.6 14.7 2.2 0.5 0.03	6.4 11.7 19.9 40.5 21.6
2011	670,802 users making 1,710,238 edits	116,187 users making 3,080,457 edits	17,315 users making 5,071,698 edits	3,713 users making 10,149,978 edits	242 users making 5,152,882 edits	83.0 14.4 2.1 0.5 0.03	6.8 12.2 20.2 40.3 20.5
2012	588,452 users making 1,510,922 edits	105,459 users making 2,823,823 edits	16,337 users making 4,798,596 edits	3,583 users making 9,943,818 edits	262 users making 5,710,551 edits	82.4 14.8 2.3 0.5 0.04	6.1 11.4 19.4 40.1 23.0
2013	593,126 users making 1,482,624 edits	101,504 users making 2,702,400 edits	15,346 users making 4,482,689 edits	3,453 users making 9,656,836 edits	237 users making 5,580,079 edits	83.1 14.2 2.2 0.5 0.03	6.2 11.3 18.8 40.4 23.3
2014	653,790 users making 1,607,790 edits	100,378 users making 2,645,121 edits	14,852 users making 4,359,655 edits	3,268 users making 9,020,907 edits	257 users making 5,518,275 edits	84.6 13.0 1.9 0.4 0.03	6.9 11.4 18.8 39.0 23.8
2015	625,241 users making 1,541,063 edits	98,985 users making 2,641,990 edits	15,432 users making 4,545,125 edits	3,535 users making 9,986,211 edits	297 users making 6,491,994 edits	84.1 13.3 2.1 0.5 0.04	6.1 10.5 18.0 39.6 25.8
2016	589,695 users making 1,441,458 edits	93,127 users making 2,485,653 edits	15,170 users making 4,536,748 edits	3,543 users making 9,911,871 edits	326 users making 7,834,023 edits	84.0 13.3 2.2 0.5 0.05	5.5 9.5 17.3 37.8 29.9
2017	601,956 users making 1,484,765 edits	95,183 users making 2,541,815 edits	15,657 users making 4,701,863 edits	3,659 users making 10,329,867 edits	338 users making 7,729,111 edits	84.0 13.3 2.2 0.5 0.05	5.5 9.5 17.6 38.6 28.9
2018	603,053 users making 1,469,945 edits	92,544 users making 2,461,278 edits	15,588 users making 4,700,190 edits	3,739 users making 10,586,953 edits	316 users making 8,123,855 edits	84.3 12.9 2.2 0.5 0.04	5.4 9.0 17.2 38.7 29.7
2019	599,171 users making 1,466,828 edits	93,747 users making 2,481,285 edits	15,787 users making 4,755,638 edits	3,808 users making 10,891,659 edits	317 users making 7,712,402 edits	84.1 13.2 2.2 0.5 0.04	5.4 9.1 17.4 39.9 28.2
2020	603,208 users making 1,476,476 edits	98,287 users making 2,639,933 edits	17,606 users making 5,301,178 edits	4,233 users making 12,007,682 edits	362 users making 8,956,939 edits	83.4 13.6 2.4 0.6 0.05	4.9 8.7 17.4 39.5 29.5
2021	548,897 users making 1,362,124 edits	95,849 users making 2,620,663 edits	18,132 users making 5,507,660 edits	4,439 users making 12,381,620 edits	376 users making 9,080,891 edits	82.2 14.4 2.7 0.7 0.06	4.4 8.5 17.8 40.0 29.3
2022	308,580 users making 761,495 edits	54,294 users making 1,491,894 edits	11,348 users making 3,514,367 edits	2,488 users making 6,292,318 edits	121 users making 3,383,209 edits	81.9 14.4 3.0 0.7 0.03	4.9 9.7 22.8 40.7 21.9

Reflections

Comparing the above to my priors, two things are apparent: (1) I did not express my expectations with sufficient precision, but also (2) while the general trend toward stratification of the editor community is apparent, when the data is sliced as above, the trend is neither as pronounced nor as consistent as I expected. Since I phrased my predictions in "prove me wrong" terms, it seems fair to say that the data has proven me at least partially wrong. (But not as wrong as I would have liked to be.)

That said, there is an unmistakable upward trend in the proportion of edits made by users with 1000 or more mainspace edits per year, from 55.4% in 2006 to 60.8% in 2011 to 69.3% in 2021, albeit with various hiccups on the year-to-year level. And if we include IP edits in the denominator (which seems reasonable since anons are Wikipedians too), the trend becomes much more pronounced, and almost consistent with what I expected to see -- although there is one year in this period in which stratification fell by 0.1%:

36.1 38.8 39.7 41.1 41.9 44.2 45.3 45.7 47.5 49.3 49.9 51.6 51.5 53.7 54.3 50.1 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22	46.29 Average

(Limited to 16 years by template constraints -- 2007 represented a historic low in stratification by this metric, so this may misrepresent the overall historical picture.)

Of course, including IPs in this way is as problematic as excluding them: many IP edits are actually by logged-out registered users (although notably this would suggest that stratification is under-counted), and some individual IP users may actually make more than 1000 edits per year (which might be distributed among multiple IPs or combined with other users of a shared IP). It will be instructive to see if, as per my expectations, the above trend holds when using this metric of (edits by bands 4 and 5) / (edits by all bands and all IPs) against different ways of slicing the data, such as looking at edits across all namespaces.

It will also be interesting to see if the seeming sharp reduction in stratification in the first half of 2022 holds true for the year as a whole. It seems likely to be a seasonal artifact of some kind, or simply an effect of the year being only half complete. But it is also possible that the uptick in stratification in 2020-2021 was related to the pandemic, in which case a drop would not be entirely unexpected.

Article classes

Mainspace only, including IPs, excluding bots and redirects.

Number of edits to extant mainspace pages in each calendar year

Year	0 edits	1-9 edits	10-99 edits	100-999 edits	1,000-9,999 edits	10,000+ edits	Percent of all extant pages then existing	Percent of all edits
2001	0 pages receiving 0 edits	16,277 pages receiving 40,062 edits	700 pages receiving 10,923 edits	1 pages receiving 125 edits	0 pages receiving 0 edits	0 pages receiving 0 edits	0.0 95.9 4.1 0.0058 0.0 0.0	78.4 21.4 0.2 0.0 0.0
2002	1,515 pages receiving 0 edits	84,742 pages receiving 212,827 edits	10,013 pages receiving 187,215 edits	72 pages receiving 10,934 edits	0 pages receiving 0 edits	0 pages receiving 0 edits	1.6 88.0 10.4 0.1 0.0 0.0	51.8 45.6 2.7 0.0 0.0
2003	41,308 pages receiving 0 edits	110,676 pages receiving 386,833 edits	28,909 pages receiving 619,202 edits	614 pages receiving 100,047 edits	1 pages receiving 2,072 edits	0 pages receiving 0 edits	22.8 61.0 15.9 0.3 0.00055 0.0	34.9 55.9 9.0 0.2 0.0
2004	18,408 pages receiving 0 edits	282,862 pages receiving 1,105,895 edits	109,810 pages receiving 2,483,135 edits	4,412 pages receiving 843,112 edits	38 pages receiving 58,745 edits	0 pages receiving 0 edits	4.4 68.1 26.4 1.1 0.0091 0.0	24.6 55.3 18.8 1.3 0.0
2005	38,282 pages receiving 0 edits	490,510 pages receiving 2,093,430 edits	272,202 pages receiving 6,555,451 edits	18,192 pages receiving 3,977,780 edits	417 pages receiving 721,682 edits	1 pages receiving 20,875 edits	4.7 59.8 33.2 2.2 0.1 0.00012	15.7 49.0 29.8 5.4 0.2
2006	57,995 pages receiving 0 edits	737,463 pages receiving 3,202,151 edits	549,315 pages receiving 14,474,110 edits	55,407 pages receiving 13,155,672 edits	2,272 pages receiving 4,116,034 edits	3 pages receiving 39,844 edits	4.1 52.6 39.2 4.0 0.2 0.00021	9.2 41.4 37.6 11.8 0.1
2007	134,523 pages receiving 0 edits	1,081,657 pages receiving 4,395,826 edits	658,753 pages receiving 17,582,512 edits	73,512 pages receiving 17,635,961 edits	2,855 pages receiving 4,644,323 edits	0 pages receiving 0 edits	6.9 55.4 33.8 3.8 0.1 0.0	9.9 39.7 39.8 10.5 0.0
2008	246,515 pages receiving 0 edits	1,469,786 pages receiving 5,517,195 edits	674,533 pages receiving 17,852,482 edits	70,064 pages receiving 16,500,974 edits	2,014 pages receiving 3,106,795 edits	1 pages receiving 10,639 edits	10.0 59.7 27.4 2.8 0.1 0.00004	12.8 41.5 38.4 7.2 0.0
2009	382,030 pages receiving 0 edits	1,783,144 pages receiving 6,322,674 edits	678,320 pages receiving 17,728,746 edits	63,812 pages receiving 14,557,327 edits	1,337 pages receiving 2,024,791 edits	1 pages receiving 10,480 edits	13.1 61.3 23.3 2.2 0.045 0.000034	15.6 43.6 35.8 5.0 0.0
2010	587,045 pages receiving 0 edits	1,976,355 pages receiving 6,728,986 edits	669,051 pages receiving 17,322,497 edits	58,891 pages receiving 13,121,826 edits	937 pages receiving 1,400,110 edits	0 pages receiving 0 edits	17.8 60.0 20.3 1.8 0.028 0.0	17.4 44.9 34.0 3.6 0.0
2011	803,286 pages receiving 0 edits	2,148,713 pages receiving 7,003,212 edits	631,295 pages receiving 16,195,378 edits	49,838 pages receiving 10,588,358 edits	682 pages receiving 1,059,748 edits	0 pages receiving 0 edits	22.1 59.1 17.4 1.4 0.018 0.0	20.1 46.5 30.4 3.0 0.0
2012	935,465 pages receiving 0 edits	2,363,481 pages receiving 7,414,668 edits	622,177 pages receiving 15,855,405 edits	46,152 pages receiving 9,612,009 edits	602 pages receiving 939,281 edits	0 pages receiving 0 edits	23.6 59.6 15.7 1.2 0.015 0.0	21.9 46.9 28.4 2.8 0.0
2013	1,204,533 pages receiving 0 edits	2,410,426 pages receiving 7,445,397 edits	615,280 pages receiving 15,537,302 edits	42,345 pages receiving 8,608,469 edits	451 pages receiving 679,450 edits	0 pages receiving 0 edits	28.2 56.4 14.4 1.0 0.01 0.0	23.1 48.1 26.7 2.1 0.0
2014	1,399,920 pages receiving 0 edits	2,550,167 pages receiving 7,588,228 edits	586,887 pages receiving 14,689,787 edits	37,452 pages receiving 7,593,405 edits	412 pages receiving 682,692 edits	1 pages receiving 10,114 edits	30.6 55.7 12.8 0.8 0.009 0.000021	24.8 48.1 24.8 2.2 0.0
2015	1,496,269 pages receiving 0 edits	2,690,202 pages receiving 8,081,362 edits	637,381 pages receiving 15,958,026 edits	41,725 pages receiving 8,527,608 edits	505 pages receiving 788,437 edits	0 pages receiving 0 edits	30.7 55.3 13.1 0.9 0.01 0.0	24.2 47.8 25.6 2.4 0.0
2016	1,497,344 pages receiving 0 edits	2,951,877 pages receiving 8,871,883 edits	658,044 pages receiving 16,361,438 edits	41,801 pages receiving 8,511,744 edits	518 pages receiving 840,940 edits	1 pages receiving 19,276 edits	29.1 57.3 12.8 0.8 0.01 0.000019	25.6 47.3 24.6 2.4 0.1
2017	1,739,794 pages receiving 0 edits	2,966,260 pages receiving 8,734,177 edits	661,123 pages receiving 16,522,235 edits	42,185 pages receiving 8,587,348 edits	483 pages receiving 793,090 edits	0 pages receiving 0 edits	32.2 54.8 12.2 0.8 0.0089 0.0	25.2 47.7 24.8 2.3 0.0
2018	1,681,862 pages receiving 0 edits	3,276,174 pages receiving 9,543,707 edits	664,689 pages receiving 16,456,293 edits	41,067 pages receiving 8,315,816 edits	472 pages receiving 742,264 edits	0 pages receiving 0 edits	29.7 57.8 11.7 0.7 0.0083 0.0	27.2 46.9 23.7 2.1 0.0
2019	1,958,489 pages receiving 0 edits	3,232,419 pages receiving 9,313,981 edits	671,530 pages receiving 16,703,349 edits	41,483 pages receiving 8,332,984 edits	471 pages receiving 758,188 edits	0 pages receiving 0 edits	33.2 54.7 11.4 0.7 0.0079 0.0	26.5 47.6 23.7 2.2 0.0
2020	1,776,752 pages receiving 0 edits	3,607,917 pages receiving 10,589,176 edits	732,262 pages receiving 17,942,472 edits	42,376 pages receiving 8,454,616 edits	540 pages receiving 942,328 edits	3 pages receiving 44,565 edits	28.8 58.6 11.9 0.7 0.0087 0.000048	27.9 47.3 22.3 2.5 0.1
2021	1,984,936 pages receiving 0 edits	3,644,001 pages receiving 10,603,555 edits	735,291 pages receiving 18,072,335 edits	43,589 pages receiving 8,776,762 edits	593 pages receiving 909,618 edits	1 pages receiving 10,066 edits	31.0 56.9 11.5 0.7 0.0092 0.000015	27.6 47.1 22.9 2.4 0.0
2022	3,135,960 pages receiving 0 edits	2,999,590 pages receiving 7,351,937 edits	357,852 pages receiving 8,309,494 edits	14,888 pages receiving 2,865,400 edits	184 pages receiving 278,994 edits	2 pages receiving 23,992 edits	48.2 46.1 5.5 0.2 0.0028 0.00003	39.0 44.1 15.2 1.5 0.1

Editor age

Excludes bots. Mainspace only.

For each year, the number of registered users who made a mainspace edit who had made their first mainspace edit N years ago.

	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21
2001	1030
2002	1743	223
2003	7542	665	163
2004	33947	2905	584	175
2005	130601	14821	2578	571	185
2006	559985	53085	13554	2625	609	216
2007	745714	142554	40167	11694	2389	543	209
2008	652347	112089	87477	30524	9526	2002	487	182
2009	608580	83616	69358	66078	25585	8372	1912	476	172
2010	547202	73431	50475	50993	52093	21294	7243	1660	430	147
2011	547727	62932	45410	38455	41816	44652	18620	6594	1504	405	144
2012	465884	57317	36424	32532	29280	32718	36426	15895	5750	1368	377	122
2013	468746	50742	34313	27464	26336	24444	28284	31779	14480	5268	1324	360	126
2014	542580	45463	27533	24591	21314	20928	19953	23853	27231	12698	4747	1195	337	122
2015	512738	48477	27050	20670	19708	17620	17812	17217	20765	24076	11487	4332	1113	310	115
2016	472028	46796	27685	20351	16830	16358	15218	15512	15200	18288	21630	10483	4036	1038	304	104
2017	482831	46135	27994	20832	17080	14405	14307	13598	13937	13860	16578	20219	9848	3822	973	271	103
2018	468882	48686	27852	22180	17841	15061	13051	13174	12569	13180	13067	15814	19374	9489	3712	963	248	97
2019	459712	49065	29427	21436	18301	15324	13115	11534	12128	11488	12226	12082	14965	18271	8954	3531	924	251	96
2020	464423	48877	29084	22405	17600	15891	13281	11780	10567	11169	10594	11483	11505	14088	17568	8669	3454	903	253	102
2021	414560	51496	27027	20775	17034	14014	13065	11065	10082	8927	9654	9221	9943	10081	12406	15839	8055	3258	867	235	89
2022	193889	38184	22115	14597	11829	10090	8356	7883	6822	6002	5542	5943	5766	6215	6413	7880	10461	5608	2313	671	186	66

Reflections on editor age and retention

The above table likely undercounts first-year repulsion, since it goes by calendar years rather than editor years. Yet even by this metric, editor repulsion after the first year has exceeded 90% every year since 2012. Even as recently as 2020, a higher proportion of editors who joined in 2001 were still active on the project than those who joined in 2019.

Of course, editor numbers don't tell us much about edit numbers. Maybe the older editors are just kibitzers who come back to fix a typo once in a while. One simple metric for evaluating this would be the average age of editors weighted by number of edits. That is, for any given edit, how old is the editor making it likely to be?

In the steady-state case, this weighted average editor age would be constant over time. In the case of a small core of editors aging in place with nobody leaving or joining, it would grow at one year per calendar year.

The growth in weighted editor age was comparatively flat in the project's early years (likely due to the project's explosive growth in that period). But since 2006, weighted editor age has grown at a grimly consistent pace of approximately six months per year:

Average editor age weighted by number of mainspace edits in calendar year. See or edit source data.

This is not as bad as it could be, but is definitely not the mark of a healthy community. Interestingly, 2021 showed the lowest absolute increase in weighted editor age of any year since 2006, going from just 7.62 to 7.77 years. This seems likely to be a pandemic anomaly; I hereby predict that 2022 will return to trend and will be the first year in Wikipedia history in which the weighted editor age exceeds 8 years.

It is perhaps noteworthy that from 2015 to 2017 the increase was reduced to approximately 4 months per year, before skyrocketing to more than 8 months in 2018. The cause of that shift would be interesting to know -- was it due to improved new-editor retention, or were older editors editing less?

Using the metric of two-year retention (i.e. those editors who first made a mainspace edit in 2001 who also made a mainspace edit in 2003, et seq.), retention appears to have been uniformly terrible throughout the 2010s:

Percent of editors who were still editing two years after first edit. See or edit source data.

Accordingly, it seems fair to say that the 2015-2017 editor age anomaly was not due to improved retention, but to some other shift in community composition.

Turning back to the overall trend, the simplest explanation for the decline is that the community became much more hostile in the mid-to-late 2000s and has stayed that way ever since, with the "new normal" of hostility becoming self-perpetuating once it was established.

But the trend could also be explained by the community becoming better at filtering out bad or uncommitted users more quickly. In that case, we would expect that the five-year and ten-year retention rates would have improved, or would at least have become closer to the two-year retention rate: we would lose more users up front, but the ones we don't lose would stick around longer. Unfortunately, this expectation is not borne out:

Percent of editors who were still editing N years after first edit. See or edit source data.

Apart from some anomalies in the earliest years, retention has consistently dropped by roughly half from two years to five years, and again from five years to ten years. It appears that if someone is still around after two calendar years, changes in the Wikipedia environment no longer have much effect on whether they will stick around longer; the odds will be about 50/50 at year 5, and for those still around at year 5, they will be about 50/50 at year 10.

In view of that pattern, it appears that we are not actually doing a better job of finding dedicated Wikipedians. We are simply doing a more effective job of driving them away.

As a member of the anomalous entering class of 2004, I am tempted to take this a little further. Perhaps an editor's formative on-wiki experiences shape the editor's overall attitude toward the project so that editors who have had positive early experiences will not only be less likely to attrit in Y2, but also -- if they are still around in Y2 -- less likely to attrit in Y5 and Y10, even if the wiki has become a less friendly place in the meantime. Given that Wikipedia was a vastly friendlier place in its early years than it is today, this would at least partially account for the early anomalies. It would also suggest that the experience of the entering class of 2012 was uniquely bad even by 2010s standards. Of course, this is merely a hypothesis, but it appears plausible based on the data above.

In voice-exit-loyalty terms, this would mean the quality of a user's experiences during the formative period determines the user's degree of loyalty to the project going forward, i.e. how likely the user is to stick with the project when the going gets rough. Put that way, this result is scarcely surprising. But it also suggests a more damning inference: since Wikipedia is almost completely insensitive to the signal from users choosing to exit, it is precisely those users who had the best experience joining Wikipedia who have had the greatest voice in causing that experience to be so much worse for subsequent Wikipedians. We have, in essence, pulled the ladder up behind us.

This is not what good project stewardship looks like.

Age and edit band

The weighted age metric gives us only a crude idea of who is doing what. What if we break down the edit bands by age?

User and edit counts by edit band and age in 2021

	1-9 edits	10-99 edits	100-999 edits	1,000-9,999 edits	10,000+ edits	Proportions
0-1 years	401,865 users making 957,784 edits	55,825 users making 1,439,751 edits	7,329 users making 2,067,013 edits	993 users making 2,376,542 edits	44 users making 942,858 edits	12.3 18.5 26.6 30.5 12.1
2-5 years	57,709 users making 159,853 edits	16,034 users making 469,209 edits	4,037 users making 1,240,170 edits	1,011 users making 2,720,709 edits	59 users making 1,019,100 edits	2.8 8.4 22.1 48.5 18.2
6-9 years	31,568 users making 86,530 edits	8,481 users making 250,121 edits	2,338 users making 750,366 edits	686 users making 1,983,298 edits	66 users making 1,290,609 edits	2.0 5.7 17.2 45.5 29.6
10+ years	57,755 users making 157,957 edits	15,509 users making 461,582 edits	4,428 users making 1,450,111 edits	1,749 users making 5,301,071 edits	207 users making 5,828,324 edits	1.2 3.5 11.0 40.2 44.2
Proportions	70.3 11.7 6.4 11.6	54.9 17.9 9.5 17.6	37.5 22.5 13.6 26.3	19.2 22.0 16.0 42.8	10.4 11.2 14.2 64.2

One thing that stands out here is that the bulk of activity from the oldest editors comes from a small number of power users, while the newest editors are responsible for most of the edits by long-tail users. Put differently, among the oldest users it is the smallest number who make the greatest number of edits, while among the youngest users it is the greatest number who make the greatest number of edits. It also stands out that there is no editor stratum in which either of the middle-aged bands predominates. (But perhaps this just reflects a poor choice of age bands.) What did these patterns look like in 2015?

User and edit counts by edit band and age in 2015

	1-9 edits	10-99 edits	100-999 edits	1,000-9,999 edits	10,000+ edits	Proportions
1	492,363 users making 1,166,400 edits	61,951 users making 1,567,228 edits	6,168 users making 1,594,808 edits	710 users making 1,699,879 edits	23 users making 352,431 edits	18.3 24.6 25.0 26.6 5.5
5	62,262 users making 177,658 edits	17,672 users making 509,505 edits	4,040 users making 1,254,419 edits	1,002 users making 2,796,180 edits	72 users making 1,324,040 edits	2.9 8.4 20.7 46.1 21.8
9	58,951 users making 163,393 edits	15,566 users making 451,378 edits	3,898 users making 1,259,424 edits	1,306 users making 3,848,324 edits	149 users making 3,416,726 edits	1.8 4.9 13.8 42.1 37.4
None	11,665 users making 33,612 edits	3,796 users making 113,879 edits	1,326 users making 436,474 edits	517 users making 1,641,828 edits	53 users making 1,398,797 edits	0.9 3.1 12.0 45.3 38.6
Proportions	75.7 11.5 10.6 2.2	59.3 19.3 17.1 4.3	35.1 27.6 27.7 9.6	17.0 28.0 38.5 16.4	5.4 20.4 52.6 21.5

That's somewhat different, but what's really happening here? Is this just the effect of the especially prolific class of 2006 not having reached year 10 yet?

User and edit counts by edit band and age in 2016

	1-9 edits	10-99 edits	100-999 edits	1,000-9,999 edits	10,000+ edits	Proportions
1	456,936 users making 1,068,354 edits	55,632 users making 1,393,194 edits	5,603 users making 1,495,013 edits	627 users making 1,437,463 edits	26 users making 437,214 edits	18.3 23.9 25.6 24.7 7.5
5	58,947 users making 167,516 edits	17,194 users making 494,281 edits	3,995 users making 1,237,916 edits	1,007 users making 2,755,429 edits	81 users making 1,390,411 edits	2.8 8.2 20.5 45.6 23.0
9	47,543 users making 130,765 edits	12,449 users making 362,950 edits	3,121 users making 994,648 edits	994 users making 2,913,532 edits	111 users making 2,641,997 edits	1.9 5.2 14.1 41.4 37.5
None	26,269 users making 74,823 edits	7,852 users making 235,228 edits	2,451 users making 809,171 edits	915 users making 2,805,447 edits	108 users making 3,364,401 edits	1.0 3.2 11.1 38.5 46.2
Proportions	74.1 11.6 9.1 5.2	56.0 19.9 14.6 9.5	33.0 27.3 21.9 17.8	14.5 27.8 29.4 28.3	5.6 17.7 33.7 42.9

On first look, at least, that seems to be the case.

How about the First Pandemic Year of 2020?

User and edit counts by edit band and age in 2020

	1	2	3	4	None	Proportions
1	448,575 users making 1,051,682 edits	57,213 users making 1,440,988 edits	6,667 users making 1,834,137 edits	820 users making 2,034,892 edits	25 users making 461,391 edits	15.4 21.1 26.9 29.8 6.8
5	62,798 users making 173,932 edits	16,990 users making 490,990 edits	4,135 users making 1,249,222 edits	1,002 users making 2,706,929 edits	55 users making 1,040,255 edits	3.1 8.7 22.1 47.8 18.4
9	34,685 users making 94,590 edits	8,944 users making 261,693 edits	2,389 users making 744,768 edits	713 users making 2,035,233 edits	66 users making 1,296,354 edits	2.1 5.9 16.8 45.9 29.2
None	57,150 users making 156,272 edits	15,140 users making 446,262 edits	4,415 users making 1,473,051 edits	1,698 users making 5,230,628 edits	216 users making 6,158,939 edits	1.2 3.3 10.9 38.8 45.7
Proportions	71.2 11.8 6.4 10.6	54.6 18.6 9.9 16.9	34.6 23.6 14.0 27.8	16.9 22.5 16.9 43.6	5.2 11.6 14.5 68.8

There are some mildly interesting changes here, but overall I suppose the most striking thing is how even that surge in newcomer activity changed very little in the overall power structure, being largely swamped by increased editing by older editors.

Project space stratification by mainspace band

Prior to processing any data, I expected that edits in project space (which for practical purposes I define as both namespaces 4 and 5, since their purposes are seldom clearly distinguished) would show a greater level of stratification than mainspace, and that this trend would have steadily increased over time.

Edits in namespaces 4 and 5 by user's mainspace edit band

	0	1-9	10-99	100-999	1000-9999	10000+
2001	28 users making 36 edits (1.4%)	27 users making 70 edits (2.72%)	72 users making 266 edits (10.33%)	69 users making 1383 edits (53.73%)	6 users making 181 edits (7.03%)	1 users making 638 edits (24.79%)
2002	36 users making 57 edits (0.33%)	81 users making 140 edits (0.82%)	199 users making 649 edits (3.81%)	191 users making 3382 edits (19.86%)	72 users making 9916 edits (58.24%)	3 users making 2883 edits (16.93%)
2003	168 users making 306 edits (0.37%)	271 users making 646 edits (0.78%)	649 users making 3188 edits (3.85%)	629 users making 20162 edits (24.38%)	201 users making 53593 edits (64.8%)	7 users making 4810 edits (5.82%)
2004	2474 users making 5231 edits (1.12%)	2080 users making 5934 edits (1.27%)	3327 users making 22063 edits (4.71%)	2288 users making 110833 edits (23.68%)	724 users making 283701 edits (60.62%)	41 users making 40211 edits (8.59%)
2005	9114 users making 23637 edits (1.69%)	8116 users making 24772 edits (1.77%)	10175 users making 78016 edits (5.58%)	6321 users making 344536 edits (24.66%)	1819 users making 814004 edits (58.26%)	73 users making 112182 edits (8.03%)
2006	31015 users making 67021 edits (2.23%)	25443 users making 77863 edits (2.6%)	25935 users making 184709 edits (6.16%)	15007 users making 763089 edits (25.43%)	4269 users making 1694246 edits (56.47%)	183 users making 213409 edits (7.11%)
2007	47217 users making 90400 edits (2.64%)	31217 users making 86712 edits (2.54%)	28082 users making 198747 edits (5.81%)	16109 users making 864486 edits (25.28%)	4890 users making 1928978 edits (56.41%)	220 users making 250537 edits (7.33%)
2008	41124 users making 85444 edits (2.78%)	26910 users making 77934 edits (2.54%)	22399 users making 169918 edits (5.53%)	12698 users making 703062 edits (22.88%)	4370 users making 1721587 edits (56.03%)	275 users making 314907 edits (10.25%)
2009	33231 users making 63032 edits (2.3%)	21674 users making 83791 edits (3.06%)	19153 users making 152704 edits (5.58%)	11117 users making 660807 edits (24.14%)	3949 users making 1457203 edits (53.23%)	267 users making 319771 edits (11.68%)
2010	27528 users making 55031 edits (2.26%)	17987 users making 80944 edits (3.32%)	17053 users making 143971 edits (5.9%)	9564 users making 568827 edits (23.31%)	3584 users making 1307295 edits (53.58%)	266 users making 283824 edits (11.63%)
2011	26247 users making 78695 edits (3.63%)	18667 users making 60964 edits (2.81%)	17329 users making 142611 edits (6.57%)	9039 users making 537031 edits (24.76%)	3237 users making 1121091 edits (51.68%)	238 users making 228743 edits (10.55%)
2012	21779 users making 48373 edits (2.42%)	15426 users making 77620 edits (3.88%)	15215 users making 133889 edits (6.69%)	8266 users making 540901 edits (27.03%)	3075 users making 954113 edits (47.69%)	255 users making 245906 edits (12.29%)
2013	16774 users making 36933 edits (2.03%)	13184 users making 63802 edits (3.51%)	14012 users making 136147 edits (7.5%)	7541 users making 446579 edits (24.6%)	2951 users making 898063 edits (49.47%)	233 users making 233799 edits (12.88%)
2014	17561 users making 56300 edits (3.35%)	13326 users making 46690 edits (2.78%)	13086 users making 122034 edits (7.26%)	7114 users making 392267 edits (23.33%)	2735 users making 833614 edits (49.57%)	250 users making 230817 edits (13.73%)
2015	17611 users making 51446 edits (2.86%)	14099 users making 49303 edits (2.74%)	13258 users making 116993 edits (6.5%)	7055 users making 390100 edits (21.67%)	2922 users making 921999 edits (51.22%)	291 users making 270215 edits (15.01%)
2016	18836 users making 54501 edits (3.21%)	16130 users making 54209 edits (3.19%)	12987 users making 106616 edits (6.27%)	6636 users making 356859 edits (21.0%)	2853 users making 842966 edits (49.6%)	311 users making 284496 edits (16.74%)
2017	18722 users making 43477 edits (2.6%)	18177 users making 75620 edits (4.52%)	13429 users making 100569 edits (6.01%)	6717 users making 339560 edits (20.29%)	2917 users making 826762 edits (49.4%)	321 users making 287525 edits (17.18%)
2018	18361 users making 50492 edits (3.15%)	18338 users making 61843 edits (3.86%)	13047 users making 94324 edits (5.89%)	6546 users making 325424 edits (20.33%)	2931 users making 799370 edits (49.95%)	301 users making 268939 edits (16.8%)
2019	20166 users making 52110 edits (3.18%)	18463 users making 60447 edits (3.69%)	13464 users making 99192 edits (6.05%)	6520 users making 357440 edits (21.81%)	2965 users making 723550 edits (44.16%)	303 users making 345884 edits (21.11%)
2020	21416 users making 47991 edits (2.61%)	17772 users making 63290 edits (3.44%)	14076 users making 102390 edits (5.56%)	7642 users making 378537 edits (20.57%)	3374 users making 900923 edits (48.95%)	340 users making 347212 edits (18.87%)
2021	16768 users making 40128 edits (2.26%)	15775 users making 56390 edits (3.17%)	13538 users making 105782 edits (5.94%)	7667 users making 395867 edits (22.25%)	3395 users making 874523 edits (49.14%)	349 users making 306793 edits (17.24%)
2022	8308 users making 23657 edits (2.88%)	8811 users making 31179 edits (3.79%)	7218 users making 79813 edits (9.7%)	4889 users making 241522 edits (29.36%)	1868 users making 372815 edits (45.33%)	110 users making 73531 edits (8.94%)

Reflections on project space stratification

After running these initial numbers, although there is a noticeable upward trend in the percentage of project-space edits made by editors in the mainspace five-digit band, the overall degree of stratification seems to be somewhat less (or at any rate not significantly greater) than in article space. I have once again been proven at least partially wrong. Hooray!

But the biggest takeaway for me is that there's more going on in project space than I would have anticipated (1.7 million edits a year?!). I suspect that a meaningful analysis of trends in project space would have to be more granular -- trends in participation on noticeboards, wikiprojects, policy pages, and the deletion zone may all be quite different.

How about editor age? If we run the same weighted-age metric on edits to namespaces 4 and 5 that we ran above for mainspace, we get a familiar but somewhat less regular trend:

The weighted average age for editors in project space rose by about 8 months a year from 2007 to 2019, jumped by 1.1 years to 9.1 in 2020, and rose even further to a staggering 9.3 in 2021. (While the number itself is alarming, it is perhaps noteworthy that this reflects the same, possibly pandemic-related flattening in 2021 that we saw in mainspace.)

I am not quite sure what to make of the apparent drop in weighted age in 2022. It seems like the weighted age should be overstated at the middle of the year -- but if that is the case in 2022, then when the year is complete, this will be the first year in all of Wikipedia history when the weighted age of participants in project space fell from the previous year (and perhaps by as much as two years).

Again, a more granular analysis of exactly what is going on in various sub-areas of project space would probably be necessary to make sense of these numbers.

Priors

Before processing any data, I anticipate the following results:

1. User stratification, operationalized as the percentage of non-bot edits made by very active editors, will have become considerably more pronounced than in 2011.
   • This will be true regardless of whether the edit count is limited to mainspace, or whether users are grouped by their highest level of monthly activity, overall mean level of monthly activity since first edit, or in-year level of monthly activity.
2. Indeed, there will be no year since 2006 in which user stratification did not increase.
   • As above, this will be true regardless of how the data is sliced.
3. Article stratification, operationalized as the percentage of non-bot mainspace edits made to very active articles, will also have consistently increased year-on-year since at least 2006.
   • As above, this will be true regardless of how the data is sliced (in-year level of monthly activity, overall mean level of monthly activity since creation, or in-year level of monthly activity).

Code

The current rough code can be found here.

Data

CSV datasets generated by the above code, in the form of 22 annual user-page-month CSV files and one CSV file each of user and page definitions, can be found here.