322. This chapter reviews the practices in the 2020 census round regarding the demographic characteristics of persons, including in particular the core variables sex, age and marital status that are fundamental in classifying and reporting on other information from the census to foster understanding of socioeconomic and demographic issues.

323. Concerning the topic sex, the CES Recommendations highlighted that sex disaggregation of data is a fundamental requirement for gender statistics. The CESR also noted that some countries had started considering in surveys additional ”sex” (or ”gender”) response categories in addition to male-female, in order to allow persons of cross-gender or indeterminate sex to self-identify, and that such countries may, therefore, wish to attempt to record such information in the census (paras. 455-456). For this reason, the UNECE survey included a specific section with questions on sex and gender, specifying that the questions were not mandatory.

324. In the final section of the chapter, information is presented on non-core topics on marriage, fertility, infant and child mortality.

325. In the CES Recommendations for the 2020 census round, sex was designated as a core topic. Given the importance of this variable, it was stressed that information on sex (male or female) of every individual should be recorded in the census, or should be imputed if missing. As mentioned above, the CESR noted that some countries might wish to record in the census additional ”sex” (or ”gender”) response categories in addition to male-female, in order to allow persons of cross-gender or indeterminate sex to self-identify.

326. The first question asked in the UNECE survey was about how the NSO collects sex, gender and/or gender identity information for statistical purposes, where gender was defined as the socially constructed characteristics of being a woman or a man, and gender identity as the gender a person identifies with.

327. The responses to this question are presented in Table 58. All reporting countries collect the variable sex, almost equally divided among the three data sources used: 16 countries used the census only, 15 used a centralized data base such as a population register only and 13 indicated using a combination of the two sources.

328. There is a strong correlation between the type of census and the sources used to collect data on sex, as expected. Most countries with a field enumeration (12 out of 16) collect data on sex using the census only. All countries with a register-based census collect data on sex using only a centralized database, with the exception of Iceland that reported collecting data on sex using the census only, although the census in that country is based on registers.

329. Only four countries reported collecting data on gender using the census alone: three with a field enumeration census (Albania, Canada, Malta) and one with a combined census (the Republic of Moldova). Malta was also one of the two only countries that collected data on gender identity, together with the United Kingdom, using the census alone.

Topic and source	Total (out of 44 countries)	Type of census
		Field enumeration (15 countries)	Combined (16 countries)	Register-based (13 countries)
Sex – information collected using…	44	15	16	13
Census alone	16	12	3	1
Census in combination with a centralized database such as a Population Register	13	3	10	0
Centralized database such as a Population Register alone	15	0	3	12
Not collected	0	0	0	0
Gender – collected using…	4	3	1	0
Census alone	4	3	1	0
Census in combination with a centralized database such as a Population Register	0	0	0	0
Centralized database such as a Population Register alone	0	0	0	0
Not collected	33	8	13	12
Gender identity – collected using…	2	2	0	0
Census alone	2	2	0	0
Census in combination with a centralized database such as a Population Register	0	0	0	0
Centralized database such as a Population Register alone	0	0	0	0
Not collected	35	10	13	12

330. Countries where information on sex, gender or gender identity is collected – in the census or in a centralized database such as a population register – were asked to indicate what are the available categories/response options. In Germany, for both the census and the centralized database there are four options, according to the birth register: female, male, diverse, and no information. In Canada the census included a question on sex at birth with male and female as response options, and another question on gender where, in addition to male and female, respondents could write a different response. In England and Wales a gender identity question asked whether the gender with which the respondent identifies is the same as their sex registered at birth, with response options “yes” and “no” (with a write-in option for “no”). In Iceland, four categories are used: males, females, boys, and girls. In all other responding countries there are only two options: male and female.

331. In 23 of the responding countries there are different words for sex and gender in the national language(s), while in 20 countries there are no different words for sex and gender.

332. Most people do not understand the difference between sex and gender and use them interchangeably in 26 countries (74% of those responding), including 15 countries where there are different words for sex and gender in the national languages. On the contrary, the difference between the terms sex and gender is generally understood by the public in only 9 countries, including Bulgaria and Germany where there are no different words for sex and gender in the national languages.

333. Census data by sex in Germany are published for the four above mentioned categories. In all other countries they are published only for males and females.

334. Census data by gender are published only in two countries: in Canada for the categories man, woman, non-binary person, cisgender, transgender (gender diversity status); and in Spain for male, female and missing.

335. Census data by gender identity are published only in England and Wales, with the following categories: gender same as sex registered at birth; not the same, broken down into trans man, trans woman, non-binary and all other gender identities.

336. The censuses in Canada and the United Kingdom that have collected information on gender have used two different approaches.

337. Canada used a question design commonly referred to as the “two-step approach”, where a question on gender is paired with a question on sex at birth. Canada modernised their most recent censuses using gender as the default demographic for output. Canada now asks, “What was this person’s sex at birth?” as opposed to “What is this person’s sex?” as used in the 2016 census. This question’s response options of male and female remained unchanged across censuses. The next question asked, "What is this person’s gender?" with response options of “Male” and “Female” with a write-in option “Or please specify this person’s gender”. In this two-step approach, it is necessary to use responses from both parts of the question to derive gender.

338. Censuses in the United Kingdom took a different approach, and this varied between England and Wales, and Scotland. Both maintained the question “What is your sex?” In England and Wales, respondents were then asked, “Is the gender you identify with the same as your sex registered at birth?” with response options of “yes”, “no” and a write-in response. In Scotland, the second question asked, “Do you consider yourself to be trans or have a trans history?” with response options of “no” and “yes, please describe your trans status”, with a write-in option. The question includes the note “Trans is a term used to describe people whose gender is not the same as the sex they were registered at birth.”

339. The data from England and Wales showed that while there is confidence in the gender identity estimates at a national level, there are some patterns in the data that are consistent with – but do not conclusively demonstrate – that some respondents may not have interpreted the question as intended, for example, people with lower English language skills in some areas.

340. Together with sex, age is one of the most important characteristics that should be collected in a census for each person. The CES Recommendations state that information on age should be calculated based on information on date of birth (para. 457). This yields more precise information than collecting data on exact age at the census reference time. Collecting information on the date of birth allows for the tabulation of data in two ways: by year of birth and by completed years of age.

341. Of the 46 responding countries, 42 (91%) calculated the age at the census based on the date of birth. Nine of those countries also collected information at the exact age (in years and months) at the time of the census. Four countries collected only the exact age at the time of the census: Croatia and Tajikistan in a field enumeration census, Denmark and Finland in a register-based census.

	Total (out of 46 countries)	Type of census
		Field enumeration (16 countries)	Combined (16 countries)	Register-based (14 countries)
Information collected, of which…	46	16	16	14
Based only on date of birth	33	12	12	9
Based on both date of birth and exact age (in years and months) at the time of the census	9	2	4	3
Based only on exact age (in years and months) at the time of the census	4	2	0	2
Information not collected	0	0	0	0

342. The CES Recommendations included two distinct topics for marital status: legal (core topic) and de facto marital status (non-core topic). Legal marital status was defined (para. 460) as: ”The (legal) conjugal status of each individual in relation to the marriage laws (or customs) of the country (often referred to as the de jure status). Moreover, CESR recommended (at paragraph 461) that: “Information on the legal marital status of each person should be collected at least for persons aged 15 and over. However, since the minimum legal age (or the customary age) for marriage varies between countries, and since the population may also include young persons who have been married in other countries with lower minimum ages, the collection of the data for all persons is encouraged.”

343. The following basic classification of the population by marital status was recommended:

(1.0) Never married

(2.0) Married

(3.0) Widowed and not remarried

(4.0) Divorced and not remarried

344. The CES Recommendations also provided options (at paras. 464-465) for additional status categories in countries where national legislation includes provisions for registered/legal partnerships (for opposite-sex couples and/or same-sex couples), or for same-sex marriages.

345. All responding countries collected information about legal marital status (Table 60). Only two countries used a definition that was not fully compliant with the definition recommended by the CES. In the Russian Federation the question took into account information on de jure marriage and de facto marital unions, in order to reflect user needs, allow comparison with previous censuses and be more acceptable to respondents. In the United States marital status is self-reported and the help text indicates that respondents may include common law marriages, in order to allow better comparability with previous censuses, consistency with other statistical surveys, and be more acceptable to respondents.

346. Information on legal marital status was collected/produced in 20 countries for persons of all ages, and in 25 countries only for persons above a specified age: 15 years and above in 16 countries, 16 and above in 6 countries, 14 and above in France and 12 and above in Italy.

Was information on legal marital status collected/produced?	Total (out of 45 countries)	Type of census
		Field enumeration (16 countries)	Combined (16 countries)	Register-based (13 countries)
Information collected, of which…	45	16	16	13
…the definition used complied fully with the CES recommended definition	43	14	16	13
… the definition did NOT comply fully with the recommended definition	2	2	0	0
Information not collected	0	0	0	0

347. De facto marital status was defined in the CES Recommendations as “the status of each individual in terms of his or her actual living arrangements within the household being enumerated regardless of that person’s legal marital status” (para. 469). It was the first time that this topic was considered as a core topic since it was a non-core topic until the 2010 census round.

348. It was recommended that information on this topic be collected for persons of the same age categories as those for whom information on the legal marital status was collected.

349. The recommended classification (para. 470) was:

(1.0) Person living with spouse or partner (registered or in a consensual union) having usual residence in the same household

(2.0) Person not living with spouse or partner (registered or in a consensual union) having usual residence in the same household.

350. Information on the collection of data on de facto marital status in the 2020 round is presented in Table 61. Of the responding countries, 37 (80%) collected or produced information on de facto marital status, including almost all countries with a field enumeration or combined census, but less than two thirds of those with a register-based census. Countries used different methods to produce the information. The majority of countries with field enumeration or combined census used a specific question on de facto marital status (10 countries) or a general question where both legal and de facto marital statuses were listed (9 countries).

	Total (out of 46 countries)	Type of census
		Field enumeration (16 countries)	Combined (16 countries)	Register-based (14 countries)
Information collected	37	15	13	9
…through a specific question on “de facto marital status”	10	6	4	0
…through a general question on marital status, where both legal and de facto marital status were listed	9	5	4	0
…through the relationship to the reference person	8	2	3	3
…with another method	10	2	2	6
Information not collected	9	1	3	5
Classification used comply fully with CES recommended classification	31	13	12	6
Classification used does NOT comply fully with recommended classification	5	1	1	3

351. Among countries with register-based census, three used the information on relationship to the reference person and six used other methods, often including statistical models (in Denmark, Lithuania, Spain and Sweden). Almost all countries (86%) used a classification fully compliant with the CES recommendations.

352. The CES Recommendations included a number of non-core topics on the timing and duration of marriage and consensual unions, and on the fertility history of women. This information is often collected in countries where there is no universal system of vital registration and where, as a consequence, the census provides the only comprehensive source of information about fertility and population growth. Information on age of death of children can also be collected to calculate estimates of infant and child mortality

353. The UNECE survey collected from countries information about those topics. The results are presented in this section.

354. The CESR noted that that the total number and sex of children born alive – if included in the census – should be asked of all women aged 15 and older (or lower limit where significant fertility occurs at younger ages), and should include all children born alive during the women’s lifetime (including those born in previous marriages) up to the census date, but should not include stillbirths (CESR paras. 475-477). The results of the UNECE survey on this topic are presented in Table 62.

	Total (out of 45 countries)	Type of census
		Field enumeration (16 countries)	Combined (16 countries)	Register-based (13 countries)
Information collected	25	11	11	3
From women aged…
10 and above	1	1	0	0
11 and above	1	0	1	0
12 and above	3	1	2	0
13 and above	1	1	0	0
15 and above	12	4	7	1
Children counted…
All live-born children to a woman over her lifetime	21	10	10	1
Other sub-group of children	2	1	1	0
Information not collected	20	5	5	10

355. Information on the total number of live-born children was collected by over half of the responding countries (25 out of 45), including about two thirds of the countries with field enumeration or combined census, and one quarter of the countries with register-based census. This could mean that countries using administrative registers have more difficulties in collecting fertility data for census purposes, or that they have sufficiently good vital registration data not to require this (non-core) information to be collected specifically for the census.

356. Two countries collected information on different sub-groups of children from the one recommended: Belarus counted the number of all children born to a woman, and Malta counted only the first live birth to a woman.

357. The age or date of birth of children alive, and/or the age at death or date of death of children who have subsequently died can be collected in order to estimate fertility or infant/child mortality, when reliable estimates are not available from vital registration data or other sources.

358. The results of the UNECE survey on these topics are presented in Table 63. Information on the age or date of birth of children still alive was collected by only a quarter of the responding countries (10 out of 40), including about one third of the countries with field enumeration or combined census, and only one country with register-based census (Finland).

359. Information on age at death or date of death of children who have died was collected by only three countries (8%): Finland, Kyrgyzstan and Switzerland.

	Total (out of 40 countries)	Type of census
		Field enumeration (16 countries)	Combined (15 countries)	Register-based (9 countries)
Age or date of birth of children still alive
Information collected	10	5	4	1
Information not collected	30	11	11	8
Age at death or date of death of children who have died
Information collected	3	1	1	1
Information not collected	36	14	14	8

360. Information on dates/duration of marriages and consensual unions is valuable for fertility statistics and extends the knowledge that can be derived from data on number of live-born children. The CESR included two non-core topics on the dates of legal marriages of ever-married women (paras. 478-479), and on the dates of the beginning of the consensual unions of women having ever been in consensual union (paras. 480-481). For both topics, it was suggested to obtain information on the dates of both the first and the current union (marriage or consensual union). The results of the UNECE survey are presented in Table 64.

361. The dates of legal marriages of ever-married women were collected by one quarter of the countries (11 out of 43). Six (6) of them collected only the date of the current marriage, 2 countries collected only the date of the first marriage, and 3 countries collected both.

362. The dates of the beginning of the consensual unions were collected by only 5 countries out of 44 (11%). None of the countries with register-based census collected the information, but Spain noted that they are working to obtain this variable with good quality from administrative records.

	Total (out of 44 countries)	Type of census
		Field enumeration (16 countries)	Combined (15 countries)	Register-based (13 countries)
Date(s) of legal marriage(s) of ever-married women
Information collected, of which…	11	3	5	3
On both FIRST and CURRENT marriage	3	1	1	1
On FIRST marriage only	2	1	0	1
On CURRENT marriage only	6	1	4	1
Information not collected	32	13	10	9
Date(s) of the beginning of the consensual union(s) of women having ever been in consensual union
Information collected, of which…	5	2	3	0
On both FIRST and CURRENT marriage	2	1	1	0
On FIRST marriage only	1	1	0	0
On CURRENT marriage only	2	0	2	0
Information not collected	39	14	12	13