• Summary
• Downloads
• Explanatory Notes
• Related Information
• Past Releases

UNDERCOUNT ADJUSTMENT FACTORS


UNDERCOUNT ADJUSTMENT FACTORS

While estimates of net undercount are important for an effective understanding of the completeness of Census counts, undercount adjustment factors are the means for adjusting Census counts.

The undercount adjustment factor is the ratio of the PES population estimate to the actual Census count. This factor can be applied to the Census count for any category to indicate how many people should have been counted in that Census category. Table 12 provides corresponding PES population estimates, Census counts and net undercount adjustment factors for the categories previously discussed.

The undercount adjustment factor should not be used alone to derive an alternative measure of the Estimated Resident Population (ERP). Official population estimates include additional data and adjustments for usual residents of Australia who are temporarily overseas. For information on the calculation of ERP, see the ABS publication Australian Demographic Statistics, December quarter 2011 (cat. no. 3101.0), released on 20 June 2012.

12 NET UNDERCOUNT, Population estimates, Census counts and Undercount adjustment factors - 2011
		PES population estimate(a)		Census count(b)	Net undercount		Undercount adjustment factor
		no.	SE	no.	no.	SE	no.	SE
Australia		21 879 261	38 315	21 504 721	374 540	38 315	1.017	0.002
State/territory of usual residence
	New South Wales	7 054 301	26 865	6 917 654	136 647	26 865	1.020	0.004
	Victoria	5 410 949	17 864	5 354 043	56 906	17 864	1.011	0.003
	Queensland	4 409 948	17 431	4 332 733	77 215	17 431	1.018	0.004
	South Australia	1 613 850	6 045	1 596 567	17 283	6 045	1.011	0.004
	Western Australia	2 297 111	12 004	2 239 193	57 918	12 004	1.026	0.005
	Tasmania	505 616	3 076	495 355	10 261	3 076	1.021	0.006
	Northern Territory	227 675	3 074	211 959	15 716	3 074	1.074	0.015
	Australian Capital Territory	359 812	3 055	357 217	2 595	3 055	1.007	0.009
Sex
	Male	10 872 858	24 534	10 632 062	240 796	24 534	1.023	0.002
	Female	11 006 403	20 772	10 872 659	133 744	20 772	1.012	0.002
Age group (years)
	0-4	1 438 176	8 017	1 420 913	17 263	8 017	1.012	0.006
	5-9	1 371 672	7 781	1 351 746	19 926	7 781	1.015	0.006
	10-14	1 376 784	7 664	1 370 870	5 914	7 664	1.004	0.006
	15-19	1 441 530	9 044	1 405 635	35 895	9 044	1.026	0.006
	20-24	1 568 558	12 812	1 460 410	108 148	12 812	1.074	0.009
	25-29	1 605 452	13 444	1 512 816	92 636	13 444	1.061	0.009
	30-34	1 498 425	10 407	1 453 479	44 946	10 407	1.031	0.007
	35-39	1 537 123	9 424	1 519 916	17 207	9 424	1.011	0.006
	40-44	1 563 684	8 856	1 542 661	21 023	8 856	1.014	0.006
	45-49	1 509 411	8 063	1 503 920	5 491	8 063	1.004	0.005
	50-54	1 460 951	8 411	1 447 204	13 747	8 411	1.009	0.006
	55+	5 507 492	11 500	5 515 151	-7 659	11 500	0.999	0.002
Registered marital status
	Never married(c)	10 490 920	29 990	10 105 325	385 595	29 990	1.038	0.003
	Widowed, divorced or separated	2 915 337	14 630	2 939 608	-24 271	14 630	0.992	0.005
	Married	8 473 004	18 737	8 459 788	13 216	18 737	1.002	0.002
Indigenous status
	Indigenous	662 335	14 274	548 147	114 188	14 274	1.208	0.026
	Non-Indigenous	21 216 926	37 272	19 898 127	1 318 799	37 272	1.066	0.002
	Not stated(d)	-	-	1 058 447	-	-	-	-
Country of birth
	Australia	16 078 800	30 156	15 016 402	1 062 398	30 156	1.071	0.002
	England	955 734	7 049	911 539	44 195	7 049	1.048	0.008
	New Zealand	529 937	6 344	483 401	46 536	6 344	1.096	0.013
	China	374 935	8 934	318 970	55 965	8 934	1.175	0.028
	India	327 051	6 075	295 357	31 694	6 075	1.107	0.021
	Italy	194 287	2 513	185 403	8 884	2 513	1.048	0.014
	Vietnam	201 125	4 313	185 030	16 095	4 313	1.087	0.023
	Philippines	188 325	3 603	171 219	17 106	3 603	1.100	0.021
	South Africa	157 387	3 383	145 675	11 712	3 383	1.080	0.023
	Scotland	135 002	2 208	133 420	1 582	2 208	1.012	0.017
	Other overseas	2 736 677	15 894	2 462 873	273 804	15 894	1.111	0.006
	Not stated(d)	-	-	1 195 432	-	-	-	-
- nil or rounded to zero (including null cells)
(a) PES estimate of the number of people who should have been counted in the Census.
(b) Includes imputed persons in non-responding dwellings.
(c) Includes those who are living with a de facto partner and have never been in a registered marriage.
(d) People whose Census form was either not received or partially completed.