Electronic Supplementary Material

Although household definitions varied over time and across countries, Ruggles and Brower (2003), found such small changes did not have significant effects on total households enumerated. We, however, provide representative definitions used for the most important nations evaluated in our analyses (i.e., those featured in Figures 2 and 3). We then provide sources for all household data. In the final section, we highlight irregular data which do not conform to the “housekeeping” or the “housing unit” definitions of households.

Household Definitions

Australia (1981): “A household is either a person living alone or a group of people living together as a single domestic unit with common eating arrangements. It is possible for more than one household to live in more than one house or structure (United Nations, 1989).”

Bahrain (1981): “A social unit, usually occupied by people related to one another sharing their daily living, an individual person living alone or two or more unrelated individuals sharing living expenses (United Nations, 1989).”

Belgium (1981): “A household consists either of a person who usually lives alone, or two or more persons, related or unrelated, who usually occupy a single dwelling and live together (United Nations, 1989).”

Brazil (1980): "Familia" is a group of persons linked by parentage or domestic dependency who live in the same housing unit, a person who lives alone in a private housing unit, or a group of not more than 5 unrelated people who live in a private housing unit (United Nations, 1989).”

Canada (1986): “Refers to a person or group of persons (other than foreign residents) who occupy a dwelling and do not have a usual place of residence elsewhere in Canada. For census purposes, every person is a member of one and only one household (United Nations, 1989).”

China (2000): Includes “family households” and “collective households”. Household size was calculated by dividing total population by total households (National Bureau of Statistics PRC, 2002).

Denmark (1981): “A household consists of all persons living in a single dwelling whether or not members of the same family (United Nations, 1989).”

Egypt (1976): “One person or group of persons, related or unrelated, who share the same lodging unit and partake of the same food. Servants and civilian visitors in the lodging unit on census night and household members temporarily absent on census night (e.g., night shift workers, fishermen and military persons not serving abroad) were included (United Nations, 1989).”

England & Wales (1981): “A household is either one person living alone or a group of people (who may or may not be related) living or staying temporarily at the same address with common housekeeping. Enumerators were told to treat a group of people as a household if there was any regular arrangement to share at least one meal a day, breakfast counting as a meal, or if the occupants shared a common living or sitting room (United Nations, 1989).”

Finland (1985): “Persons permanently living in the same dwelling constitutes a household-dwelling unit. By this definition, the 1985 population and housing census classified a subtenant in the same household-dwelling unit with the rest of the persons living in that dwelling (United Nations, 1989).”

France (1982): “A private household is made up of the total number of occupants of a private dwelling unit (separate and independent premises), serving as their principal place of residence (United Nations, 1989).”

Greece (1997): “A single person living on his own in a dwelling or a group of person, related or not, sharing the same dwelling, providing in common everything needed for living and having meals most of the time together (National Statistical Service of Greece, 2003).”

Hungary (2000): “The dwelling is a unit of places and rooms with specific functions (living rooms, cooking places, sanitary places etc.), generally technically (architecturally) connected to each other, intended for human accommodation, stay (home) or converted into dwelling and also suitable for living at present, which has a separate entrance from a public place, courtyard or from a collectively used place inside the building (staircase, corridor etc.)”. Household size is calculated as inhabitants per occupied dwelling (Hungarian Central Statistical Office, 2004).

India (1981): “A household is a group of persons who commonly live together and take their meals from a common kitchen unless the exigencies of work prevented any of them doing so (United Nations, 1989).”

Ireland (2013): “A household is defined as a person living alone or a group of people who live together in the same dwelling with common housekeeping arrangements (Central Statistics Office Ireland, 2009).”

Japan (1985): “Private households are defined as follows: a group of persons sharing living quarters and living expenses or a person who lives by himself occupying a dwelling house (United Nations, 1989).”

Luxembourg (1981): “A household is made up either of a single person who usually lives alone, or two or more related or unrelated persons, who usually live communally in the same dwelling (United Nations, 1989).”

Mexico (1980): “Room or rooms occupied by one or more persons where they may sleep, cook, eat and be sheltered from the weather. The entrance to the dwelling has to be independent (United Nations, 1989).”

Netherlands (2000): “A private household is composed of one or more persons living in the same accommodation and providing for their own daily needs, alone or together (Central Bureau of Statistics, 2003).”

New Zealand (1986): “A household is a group of persons, whether related or not, who live together and who normally consume at least one meal together (United Nations, 1989).”

Panama (1980): “A private household consists of one person or group of persons, including the head, relatives, guests, domestic servants, etc. (United Nations, 1989).”

Philippines (1980): “Usually consists of a group of persons who sleep in the same dwelling unit and have common arrangements for the preparation and consumption of food (United Nations, 1989).”

South Korea (1980): “A private household is defined as a person who makes provision for his food or other essentials for living or a group of two or more persons who make common provision for food or other essentials for living. Excluding persons not living in households (United Nations, 1989).”

Seychelles (1994): Households are made up of, “groups sharing the same cooking pot (Management and Information Systems Division, 2004).”

Singapore (1980): “A private household refers to a group of two or more persons living together in the same census house and sharing common food arrangements which includes one or more of the processes of buying, cooking, serving and eating. It also includes a person living alone or a person living with others but having his own food arrangements (United Nations, 1989).”

Sweden (1985): “Person or persons who were registered in the same municipality and lived in the same dwelling (United Nations, 1989).”

Thailand (1980): “Private household may be (a) a one-person household, that is, a person who makes provision for his own food or other essentials for living without combining with any other person to form part of a multi-person household. He may be the owner, renter, lodger or caretaker of the house; (b) a multi-person household, that is, a group of two or more persons, related or unrelated, living together in a whole or part of a house who make common provision for food or other essentials for living (United Nations, 1989).”

Turkey (1980): “One person or group of persons with or without family relationship who live in the same part of a house, share meals, earnings and expenditures and take part in the management of the household. 5 Ratio of total population to number of households (United Nations, 1989).”

United States (1985): “A household consists of all the persons who occupy a housing unit. A house, an apartment or other group of rooms, or a single room, is regarded as a housing unit when it is occupied or intended for occupancy as separate living quarters; that is, when the occupants do not eat and live with any other persons in the structure and there is direct access from the outside or through a common hall....The count of households excludes group quarters (United Nations, 1989).”

Data Sources

Africa

Average household sizes and total household numbers from 1937 for Egypt came from Basic Statistics 1964 (Central Agency for Public Mobilisation and Statistics, 1965), and total population numbers were found in Statistical Handbook of the United Arab Republic: 1952-1966 (Central Agency for Public Mobilisation and Statistics, 1967). All remaining data for 1947–1986 were from editions of the United Nation's Demographic Yearbook series. Data for Seychelles for 1960 and 1971 came from the United Nations Demographic Yearbooks (1962 & 1974), while numbers for 1977–1994 were located in National Population & Housing Census of 2002 (Management and Information Systems Division, 2004).

Data not featured in Figures 2 and 3 included South Africa 1921 and 1926 (Office of Census and Statistics, 1931) , Morocco 1925 (Direction Genérale de l'Agriculture du Commerce et de la Colonisation, 1927), Gold Coast 1948 (The Crown Agent for the Colonies, 1950) and Uganda 1959 (Ministry of Economic Affairs, 1961). In addition the following data was collected from the United Nations Demographic Yearbook series.

Demographic Yearbook 1955: Cape Verde 1950, Guinea-Bissau 1950, and Mauritius1952.

Demographic Yearbook 1962: Basutoland 1956, Niger 1959, and Zanzibar and Pemba 1958.

Demographic Yearbook 1971: Liberia 1962, Libya 1964, Reunion 1967, Sierra Leone 1963, St. Helena 1966, Tunisia 1966, Tanzania 1967, Zambia 1969 and Zimbabwe 1962.

Demographic Yearbook 1973: Kenya 1969 and Morocco 1971.

Demographic Yearbook 1987: Algeria 1977, Benin 1979, Botswana 1981, Burundi 1979, Cameroon 1976, Congo 1984, Guinea 1983, Kenya 1979, Madagascar 1975, Mali 1976, Mauritania 1977, Mauritius 1983, Rodrigues 1983, Morocco 1982, Mozambique 1980, Reunion 1982, Rwanda 1978, Sao Tome & Principe 1981, Tunisia 1984, and Zambia 1980.

Demographic Yearbook 1995: Algeria 1987, Benin 1992, Botswana 1991, Burundi 1990, Cape Verde 1990, Central African Republic1988, Comoros 1991, Ivory Coast 1988, Malawi 1987, Mali 1987, Mauritius 1990, Namibia 1991, Niger 1988, Reunion 1990, Rwanda 1991, Sao Tome & Principe 1991, South Africa 1991, St. Helena 1987, Uganda 1991, Tanzania 1988, Zambia 1990, and Zimbabwe 1992.

Asia

All Bahrain data were found in the United Nations Demographic Yearbook series (1962, 1972, 1989, and 1997). Household size data for India 1901–1961 came from The Determinants and Consequences of Population Trends: New Summary of Findings on Interaction of Demographic, Economic and Social Factors (United Nations, 1973), and data for 1951, 1981, and 1991 were located in the United Nations Demographic Yearbook series (1956, 1989, 1997). Data for the Philippines from 1948-1990 were found in the United Nations Demographic Yearbook series (1956, 1962, 1964, 1989, 1997), and 2000 data came from the Philippines census website (http://www.census.gov.ph/). The 1931 data for Singapore came from A Report on the 1947 Census of Population (Del Tufo, 1949), and all 1966 numbers were found in Singapore Sample Household Survey: 1966 (Ministry of National Development, 1967). Data for 1947, 1957, 1970, 1980, and 1990 came from the United Nations Demographic Yearbook series (1956, 1962, 1974, 1989, 1997). All data for 2000 were located on Singapore’s Department of Statistics website, www.singstat.gov.sg .

Japanese numbers for 1893 were found in the 19th edition of Resume Statistique de L'Empire du Japon (Bureau de la Statistique Generale, 1905), and statistics for 1894–1903 came from the 20th edition of the same publication (Bureau de la Statistique Generale, 1906). Average household size data from 1920 to 1965 were located in An interpretation of the size and structure of the household in Japan over three centuries (Nakane, 1972). Total household and population numbers for 1920–1950 came from the Japan Statistical Yearbook: 1951 (Office of the Prime Minister, 1952), and those for 1955–1965 were from Japan Statistical Yearbook: 1975 (Office of the Prime Minister, 1975). All data for 1970–2000 were found in Statistical Handbook of Japan: 2003 (Japan: Statistics Bureau, 2003). The 1955–1997 data for China came from China Population Statistics: Yearbook: 1998 (Government of China, 1988). Data for 2000 came from the website of China's National Bureau of Statistics http://www.stats.gov.cn/english/ (National Bureau of Statistics PRC, 2002).

South Korea's data for 1955–1990 were located in the United Nations Demographic Yearbook series (1964, 1974, 1989, and 1997), while year 2000 data were taken from the Statistics Korea website http://kostat.go.kr/portal/english/index.action (Statistics Korea, 2002). Thailand's data for 1911 were found in Statistical Yearbook of the Kingdom of Siam 1921(Department of General Statistics, 1921), while those for 1960–1980 were located in the United Nations Demographic Yearbook series (1962, 1974, and 1989). The 1990 and 2000 data came from the website of Thailand's National Statistical Office http://web.nso.go.th/index.htm. Data for Turkey 1955–1990 were taken from the United Nations Demographic Yearbook series (1962, 1964, 1972, 1989, and 1997), and data for 2000 came from the website of the Turkish Statistical Institute http://www.turkstat.gov.tr/Start.do

Data not featured in Figures 2 and 3 included Sarawak 1960 (Joint Borneo Census Department & Jones, 1962) and Jordan 1961(Jordan, 1964) as well as data from the Demographic Yearbook series.

Demographic Yearbook 1955: Malaysia 1947 and Ryukyu Islands 1950.

Demographic Yearbook 1962: Cambodia 1958, Iran 1956, Iraq 1957, Kuwait 1957, Malaysia 1957, North Borneo 1960, Ryukyu Islands 1955, Syria 1960, and Taiwan 1956.

Demographic Yearbook 1963: Brunei 1960, Hong Kong 1961, and Ryukyu Islands 1960.

Demographic Yearbook 1971: Cambodia 1962, Hong Kong 1966, Iran 1966, Iraq 1965, Kuwait 1965 & 1970, Maldives 1965, Mongolia 1969, Republic of Vietnam 1962, Ryukyu Islands 1965 & 1970, and Sri Lanka 1963.

Demographic Yearbook 1973: Hong Kong 1971, Macau 1970, Nepal 1971, Pakistan 1968, and Syria 1970.

Demographic Yearbook 1987: Afghanistan 1979, Bangladesh 1981, Brunei 1981, Burma 1983, Hong Kong 1976 & 1981, Indonesia 1980, Iran 1976, Israel 1983, Jordan 1979, Kuwait 1975, 1980 & 1985, Malaysia 1980, Maldives 1977, Nepal 1981, Pakistan 1980, Sri Lanka 1981, United Arab Emirates 1975, and Viet Nam 1979.

Demographic Yearbook 1995: Hong Kong 1986 & 1991, Indonesia 1990, Iran 1991, Kazakstan 1989, Kyrgyzstan 1989, Macau 1991, Malaysia 1991, Nepal 1991, Oman 1993, Qatar 1986, Tajikistan 1989, Viet Nam 1989, and Yemen 1986.