1. Indicator

(a) Name: Population growth rate.

(b) Brief Definition: The average annual rate of change of population size during a specified period.

(c) Unit of Measurement: Usually expressed as a percentage.

2. Placement in the Framework

(a) Agenda 21: Chapter 5: Demographic Dynamics and Sustainability.

(b) Type of Indicator: Driving Force.

3. Significance (Policy Relevance)

(a) Purpose: The population growth rate measures how fast the size of the population is changing.

(b) Relevance to Sustainable/Unsustainable Development: Agenda 21 identifies population growth as one of the crucial elements affecting long-term sustainability (see especially paragraphs 5.3 and 5.16). Population growth, at both national and subnational levels, represents a fundamental indicator for national decision makers. Its significance must be analyzed in relation to other factors affecting sustainability. However, rapid population growth can place strain on a country's capacity for handling a wide range of issues of economic, social, and environmental significance, particularly when rapid population growth occurs in conjunction with poverty and lack of access to resources, or unsustainable patterns of production and consumption, or in ecologically vulnerable zones (see paragraphs 3.14, 3.25 and 3.26 of the ICPD Programme of Action).

(c) Linkages to Other Indicators: There are close linkages between this indicator and other demographic and social indicators, as well as all indicators expressed in per capita terms (for example, GDP per capita). Population growth usually has implications for indicators related to education, infrastructure, and employment. It is also related to human settlements and the use of natural resources, including sink capacities. Population growth can increase environmental degradation, although this is not always the case.

(d) Targets: International agreements do not establish national or global targets. A number of national governments have adopted numerical targets for the rate of population growth. In 1993, 11 percent of governments considered their rates of population growth to be too low, 45 percent were satisfied with the rate, and 44 percent considered it to be too high.

(e) International Conventions and Agreements: Not available (See 3d above).

4. Methodological Description and Underlying Definitions

The underlying concept of population growth rate as an indicator is well-known. For a country, it is generally based on either (i) an intercensal population growth rate calculated from two censuses, each adjusted for incompleteness; or (ii) from the components of population growth (adjusted for incompleteness, when necessary) during a period, namely, numbers of births, deaths and migrants.

5. Assessment of the Availability of Data from International and National Sources

As indicated above, the population growth rate can be calculated either from census data or from registration data (births, deaths and migrants). The United Nations recommends that countries take censuses every 10 years, and these data can be used to calculate an intercensal population growth rate. In recent decades most countries have carried out censuses and is widely available. For example, 204 countries or areas carried out a census during the 1990 census decade (1985 to 1994). Data on births, deaths and migrants may come from national registration systems or from special questions in demographic surveys and censuses.

National and sub-national census data, as well as data on births, deaths and migrants, are available for the large majority of countries from national sources and publications; as well as from special country questionnaires sent to national statistical offices from the Statistical Division, UN Department of Economics and Social Information and Policy Analysis (DESIPA). For all countries, census and registration data are evaluated and, if necessary, adjusted for incompleteness by the Population Division, DESIPA as part of its preparations of the official United Nations population estimates and projections. Past, current and projected population growth rates are prepared for all countries by the Population Division, DESIPA and appear in the United Nations publication, World Population Prospects: The 1994 Revision (see item 7, below).

6. Agencies Involved in the Development of the Indicator

The lead organization is the United Nations DESIPA. The contact point is the Director, Population Division, DESIPA; fax no. (1 212) 963 2147.

7. Further Information

Further references include:

Population Division, DESIPA, World Population Prospects: The 1994 Revision (United Nations publication Sales No. E.95.XIII.16, New York, 1995).

Population Division, DESIPA, Manual X: Indirect Techniques for Demographic Estimation (United Nations Sales No. E.83.XIII.2, New York, 1983).

Population Division, DESIPA, World Urbanization Prospects: The 1994 Revision (United Nations publication Sales No. E.95.XIII.12, New York, 1995).

Population Division, DESIPA, MORTPAK-LITE - The United Nations Software Package for Mortality Measurement (United Nations, New York, 1988).

Statistical Division/DESIPA, 1993 Demographic Yearbook, (United Nations Sales No. E/F.95.XIII.1, 1995).

For information about government policies regarding this indicator see:

United Nations, World Population Monitoring, 1993 (United Nations Sales No. E.95.XIII.8., New York, 1995).

United Nations, Results of the Seventh United Nations Population Inquiry Among Governments (New York, 1995, ST/ESA/SER.R/140).

NET MIGRATION RATE
Social	Chapter 5	Driving Force

1. Indicator

(a) Name: Net migration rate.

(b) Brief Definition: Ratio of the difference between the number of in-migrants and out-migrants from a particular area during a specified period to the average population of that area during the period considered. International and internal migration are discussed separately in sections 4 and 5 below.

(c) Unit of Measurement: The indicator is usually expressed as per thousand population.

2. Placement in the Framework

(a) Agenda 21: Chapter 5: Demographic Dynamics and Sustainability

(b) Type of Indicator: Driving Force.

3. Significance (Policy Relevance)

(a) Purpose: The net migration rate measures geographical mobility of population. Migration is one of the basic demographic events -- birth and death are the others -- that directly influence the size of population in an area.

(b) Relevance to Sustainable/Unsustainable Development: Net migration is a major force of demographic redistribution. At the international level, migration (people) is one of three important flows along with commodities (goods and services), and capital (money), that go beyond the traditional boundaries of a sovereign state. Within countries, migration both influences and is influenced by economic, social, environmental and political events. Increases of net migration linked to a loss of livelihood can be a symptom of unsustainability.

Migration is often seen as an economic phenomenon--in discussions of labour migration from rural to urban areas or from the developing countries to the developed countries, for example. It can also be a political phenomenon, as with asylum seekers and refugees. Recently, linkages with environmental factors are receiving increasing attention, as in the cases of "environmental refugees" and migration to ecologically fragile areas. The significance of migration to national policy makers does not rest only in its size, but also in its composition. Such migrant characteristics as age, sex, fertility level, educational background, occupation, and skill levels have profound implications for development in both the sending and the receiving areas or countries.

(c) Linkages to Other Indicators: The net migration rate is considered to have strong associations with economic, social, and environmental indicators. There are close linkages between this indicator and other demographic indicators, including urbanization-related indicators. In addition, migration rates can be associated with natural resource depletion, desertification, and land use change.

(d) Targets: International agreements do not establish national or global targets. Nearly all national governments regulate international migration, and many governments have policies intended to influence internal migration flows.

(e) International Conventions and Agreements: Not available.

4. Methodological Description and Underlying Definitions

(a) Underlying Definitions and Concepts: See section 4b below.

(b) Measurement Methods:

i) Net internal migration rate: The net migration rate for particular areas within a country is usually estimated on the basis of the number of persons reporting that they changed residence from outside to within the area of interest during a given period and those reporting that they changed residence from within to without the area of interest during the same period. Those reports are usually made only at the time of a census. A few countries maintaining continuous population registers have access to the required information on a yearly basis. Both censuses and population registers also produce information on the total population in the area of interest that allows the estimation of the denominator for the calculation of a net migration rate. When reliable direct information about in- and out-migration is unavailable, net migration can be estimated indirectly, as a residual factor when other sources of population change--births, deaths, and, in some cases, changes of boundaries of cities or other units--have been estimated separately (see section 5b below).

ii) Net international migration rate: Ideally, the net migration rate for a country should be derived directly from the number of immigrants to and emigrants from that country over a given period, and a count of the average population size of the country during that period. However, few countries gather sufficiently comprehensive international migration statistics on a continuous basis to allow direct calculation of the net migration rate. Therefore, the rate must often be estimated indirectly from other information. The most common estimation approach is to calculate the net migration rate as the difference between the growth rate of a country's population over a certain period and the rate of natural increase of that population (itself being the difference of the birth rate and the death rate). Such calculations are usually made for intercensal periods. Before estimating the net migration rate in this way, data must be evaluated and, if necessary, adjusted for differential levels of census under-enumeration between censuses and for errors in the estimation of the birth or death rates of a country. Other indicators of migration such as the percentage of the population born outside the country (a "stock" measure) are often used instead of the net migration rate.

(c) The Indicator in the DSR Framework: The indicator is a subcomponent of population change. As such it is regarded as a Driving Force indicator.

(d) Limitations of the Indicator: The definitions of immigrant and emigrant used by different countries and even for different data sources within a single country vary considerably, thus compromising the comparability and interpretation of the indicator. The data are often poorly measured restricting the usefulness for modelling purposes. Illegal immigrants are not captured by the census or survey statistics.

(e) Alternative Definitions: Alternative indicators of international migration, such as the stock of foreign-born persons in a country, are often used.

5. Assessment of the Availability of Data from National and International Sources

i) Net internal migration rate: Censuses are the major source of information on internal migration. They vary, however, in the type of data they collect and the way in which the information obtained is coded and tabulated. The questions most commonly included in censuses that indicate the occurrence of some change of residence are: current place residence and place of residence at a specific time before the census; current and previous place of residence, and length of stay in current residence; place of birth. Most countries code place of residence in terms of major geographical subdivision (state, department, province etc.) although use of a finer subdivision of the territory is often useful. Some countries record the urban or rural nature of the place of residence involved. However, net rural-urban migration is more likely to be derived from indirect estimation procedures than directly from census data. In general, data on internal migration gathered by censuses remain under exploited and there is no comprehensive source of information of net migration rates between different units within countries, except for countries with a population register.

(ii) Net international migration rate: Direct and comprehensive data on international migration movements are not available for most countries or areas of the world. However, the Population Division, UN Department of Economics and Social Information and Policy Analysis (DESIPA) takes into account the available direct and indirect evidence to derive net migration estimates, which are published as part of the biennial estimates and projections of population. Population registers are the data sources most likely to yield the information needed to calculate the net migration rate, but only a few developed countries maintain such registers. Immigration statistics derived from the administrative procedures involved in admitting foreigners for residence do not provide good measures of flows nor are they sufficiently comprehensive to permit the estimation of migration rates as they do not reflect the migration of citizens. In a few countries, arrival and departure statistics derived as part of migration control at ports of entry provide information on the number of immigrants and emigrants. However, most countries gathering arrival and departure statistics fail to differentiate international migrants from other travellers and consequently those data cannot be used to derive net migration rates.

For both internal and international migration, both absolute data and rate of change are required by policy makers. The composition of migrants would also be useful.

6. Agencies Involved in the Development of the Indicator

The lead organization is the United Nations DESIPA. The contact point is the Director, Population Division, DESIPA; fax no. 1 212 963 2147.

7. Further information

i) Net internal migration rate

Patterns of Urban and Rural Population Growth (United Nations publication, Sales No. E.79.XIII.9).

Internal Migration of Women in Developing Countries (United Nations publication, Sales No. E.94.XIII.3).

Courgeau, Daniel, Méthodes de Mesure de la Mobilité Spatiale (Institut National d'Etudes Démographiques, Paris, 1988).

ii) Net international migration rate

World Population Prospects: The 1994 Revision (United Nations publication, Sales No. E.95.XIII.16, New York, 1995).

1989 Demographic Yearbook (United Nations publication, Sales No. E/F.90.XIII.1).

Trends in Total Migrant Stock, Revision 1, database maintained by the Population Division, DESIPA, 1995 (POP/1B/DB/95/1).

Recommendations on International Migration Statistics (United Nations publication, Sales No. F.79.XVII.18).

Consolidated Statistics of all International Arrivals and Departures: A Technical Report (United Nations publication, Sales No. E.85.XVII.8).

National Data Sources and Programmes for Implementing the United Nations Recommendations on Statistics of International Migration (United Nations publication, Sales No. E.86.XVII.22).

Measuring International Migration: Theory and Practice, International Migration Review (Staten Island, New York), vol. 21, No. 4 (Winter).

TOTAL FERTILITY RATE
Social	Chapter 5	Driving Force

1. Indicator

(a) Name: Total fertility rate.

(b) Brief Definition: The average number of children that would be born to a woman in her lifetime, if she were to pass through her childbearing years experiencing the age specific fertility rates for a given period.

(c) Unit of Measurement: The total fertility rate is usually expressed as per woman or per thousand women.

2. Placement in the Framework

(a) Chapter 5: Demographic Dynamics and Sustainability.

(b) Type of Indicator: Driving Force.

3. Significance

(a) Purpose: This is one of the most commonly used summary indicators of the level of fertility. An important property of the total fertility rate is that it is not affected by the age distribution of the population, although it can be affected by rapid changes in birth timing.

(b) Relevance to Sustainable/Unsustainable Development: The International Conference on Population and Development (ICPD) Programme of Action encourages countries to take the necessary steps to complete a demographic transition, understanding that an imbalance between demographic rates and social, economic and environmental goals, together with unsustainable patterns of production and consumption, has serious implications for sustainable development. In countries where fertility is still high, large young populations create major challenges for health services, education and employment (paragraphs 6.3, 6.4, and 6.6). As such it represents a leading indicator of future change.

(c) Linkages to Other Indicators: This indicator has close linkages with other demographic indicators, particularly with the population growth rate. The ICPD Programme of Action also emphasizes the interrelationships between fertility and mortality levels, the empowerment of women, and education particularly of women and girls.

(d) Targets: International agreements do not establish specific national or global targets, although the ICPD Programme of Action encourages Governments to bring about the demographic transition. Some national governments have established quantitative goals for total fertility rate. As of 1993, 12 per cent of governments perceived their levels of fertility as being too low, 44 per cent as satisfactory, and 45 per cent as too high (sec DESIPA, World Population Monitoring, 1995 listed in section 7 below).

(e) International Conventions and Agreements: See section 3d above.

4. Methodological Description and Underlying Definitions

Where data on births by age of mother are of good quality, or adjustments for age miss-statement and incompleteness can be made, the total fertility rate is directly calculated as the sum of age-specific fertility rates, or five times the sum if data are given in five-year age groups. (An age-specific fertility rate is calculated as the ratio of annual births to women at a given age to the population of women of the same age.) When data on births by age of mother are unavailable from registration systems or maternity history data in sample surveys, the total fertility rate can be calculated through indirect methods based on special questions asked in censuses or demographic surveys. For information on these indirect estimates, see Manual X and U.C. - LITE (see section 7 below).

5. Assessment of the Availability of Data from National and International Sources

Collected by the United Nations on a regular basis and available for most countries from vital registration systems or surveys. For all countries, census and registration data are evaluated and, if necessary, adjusted for incompleteness by the Population Division, Department of Economics and Social Information and Policy Analysis (DESIPA) as part of its preparations of the official United Nations population estimates and projections. Past, current and projected population growth rates are prepared for all countries by the Population Division, DESIPA and appear in the United Nations publication, World Population Prospects: The 1994 Revision (see section 7 below).

Most countries tabulate data from birth registration systems at the sub-national level. Surveys are generally designed to provide estimates for major regions within countries as well as at the national level. Less frequently the sample design permits the examining action of this indicator at state, provincial or lower administrative levels.

6. Agencies Involved in the Development of the Indicator

The lead organization is the United Nations Department of Economics and Social Information a Policy Analysis (DESIPA). The contact point is the Director, Population Division, DESIPA; fax no. (1 212) 963-2147.

7. Further Information

Population Division, DESIPA, World Population Prospects: The 1994 Revision (United Nations Sales No. E.95.XIII.16, New York, 1995).

Population Division, DESIPA, Manual X: Indirect Techniques for Demographic Estimation (United Nations Sales No. E.83.XIII.2, New York, 1983).

Population Division, DESIPA, MORTPAK-LITE - The United Nations Software Package for Mortality Measurement (United Nations, New York, 1988).

Population Division, DESIPA, World Population Monitoring, 1993 (United Nations publication, Sales No. E. 95.XIII.8, New York, 1995).

Programme of Action of the International Conference on Population and Development, Report of the International Conference on Population and Development, Cairo, Egypt, September 5-13, 1994. (United Nations Document - A/CONF. 171/13).

Statistical Division, DESIPA, 1993 Demographic Yearbook (United Nations Sales No.E/F.95.XIII.1,1995).

 

POPULATION DENSITY
Social	Chapter 5	State

1. Indicator

(a) Name: Population density.

(b) Brief Definition: The total population size of a country or area divided by its surface area.

(c) Unit of Measurement: Usually expressed as population per square kilometer.

2. Placement in the Framework

(a) Agenda 21: Chapter 5: Demographic Dynamics and Sustainability.

(b) Type of Indicator: State.

3. Significance (Policy Relevance)

(a) Purpose: This indicator measures concentration of the human population in reference to space. Population density can be used as a partial indicator of human requirements and activities in an area. More refined indicators--such as number of persons per unit of habitable or cultivable land--may be more useful for analytic purposes. Similarly, disaggregation of the indicator to urban size categories would be useful in conjunction with other human settlement indicators.

(b) Relevance to Sustainable/Unsustainable Development: This indicator is most useful at the sub-national level. Agenda 21 makes specific references to population density in relation to desertification (Chapter 12) and to freshwater and solid wastes in urban areas (Chapters 18 and 21). In rural areas, demographic factors, working interactively with other factors such as ecological endowments and commercialization of agriculture, may place pressure on land resources. Higher or growing population density can threaten sustainability of protected forest area and ecologically fragile or marginal land. At the same time, population density is considered by some to be a driving-force of technological change in production, and high concentration of population in a limited area is the main defining feature of urban areas. High concentration of population also means more local demand for employment, housing, amenities, social security and services, and environmental infrastructure for sanitation and waste management, which may tax governments' management ability.

(c) Linkages to Other Indicators: This indicator has close linkages with other demographic indicators, particularly the population growth rate, net migration rate, life expectancy at birth and total fertility rate as well as human settlement indicators. In order to understand impacts of this indicator, it should be examined in conjunction with location of resources and systems of production and distribution. Higher population densities generally mean increased reliance on resource imports and the export of goods, as well as environmental impacts such as solid waste disposal, and emissions to air and water. Areas with high population densities tend to rely on the resources of less populated hinterlands, and thereby increase the risk of exceeding regional carrying capacities for stock and sink resources. With sub-national data, relationships to ecosystems, urban issues, and arable land, for example, can be addressed at a more local level.

(d) Targets: International agreements do not establish national or global targets.

(e) International Conventions and Agreements: Not available (see section 3d above).

4. Methodological Description and Underlying Definitions

(a) Underlying Definitions and Concepts: This indicator is well established.

(b) Measurement Methods: By definition, population density is calculated as population size divided by surface area. Surface area data, as collected by the Statistical Division, UN Department of Economics and Social Information and Policy Analysis (DESIPA), represent the total surface area, comprising land area and inland waters (assumed to consist of major rivers and lakes) and excluding only polar regions and uninhabited islands. In practice, the definition differs among countries, but is sufficiently comparable for interpretation and analysis.

(c) The Indicator in the DSR Framework: Population density represents a demographic State indicator.

(d) Limitations of the Indicator: The significance of the indicator is limited in countries which serve as international hinterlands importing all their food and natural resources. Large uninhabited areas, such as deserts, tend to distort the indicator. Disaggregation to the ecumene, or other sub-national areas, may be difficult in many countries.

(e) Alternative Definitions: Total land area instead of total area could represent a useful alternative definition.

5. Assessment of the Availability of Data from International and National Sources

Collected by the United Nations on a regular basis and available for all countries at the national level. For all countries, the population data, which provide the numerator for calculating density, are evaluated and, if necessary, adjusted for incompleteness by the Population Division/DESIPA as part of its preparations of the official United Nations population estimates and projections. Past, current and projected population figures for population density are prepared for all countries by the Population Division/DESIPA and appear in the United Nations publication, World Population Prospects: The 1994 Revision (see section 7 below).

Population density can be calculated for sub-national areas from census data available in most countries. The United Nations does not produce sub-national estimates of population density. However, such estimates are available from certain regional institutions, such as Eurostat.

6. Agencies Involved in the Development of the Indicator

The lead agency is the United Nations Department for Economic and Social Information and Policy Analysis (DESIPA). The contact point is the Director, Population Division, DESIPA; fax no. (1 212) 963 2147).

7. Further Information

Population Division, DESIPA, World Population Prospects: The 1994 Revision (United Nations Sales No. E.95.XIII.16, New York, 1995).

Statistical Division, DESIPA, 1993 Demographic Yearbook (United Nations Sales No.E/F.95.XIII.1, 1995).