Statistical Yearbook for Asia and the Pacific 2011
Statistical methods
The methods of compiling data and metadata for this Yearbook, and of calculating the indicators and data aggregates, are described in the following sections.
Compilation of data and metadata

The Yearbook presents data of 58 regional ESCAP member countries compiled from United Nations agencies and other international sources. World, regional, subregional and economic aggregates are also presented, most of which are calculated by ESCAP. The regional ESCAP member countries include members and associate members of ESCAP that are geographically located in the Asia-Pacific region. The Yearbook contains data for selected years. Data for all available years may be accessed from the online database at

Country-level data have been collected from international sources of official statistics. For each indicator, the definition and source of data, along with other metadata, is given in the technical notes section of the Yearbook. To collect the most recent available data for each indicator, ESCAP researches online and print publications, consults experts on specific indicators and monitors the release dates of international reports and databases. The Yearbook aims to present the most recent, internationally comparable data available as of 20 June 2011. In order to maximize comparability, high quality, internationally comparable data sources have been used. Nonetheless, differences in statistical methods may still exist across countries; and, while aiming for international comparability, ESCAP statisticians do not have specialised expertise in all the areas covered in the Yearbook and thus cannot ensure full comparability. The status of each data point, which specifies whether the original data source is (a) a country or (b) an international agency, is available in the online database.

On the basis of the country-level data, ESCAP calculates:

  • Additional indicators (growth rates, periods averages or data relative to the population, land area, economy, etc.);1 and
  • Aggregates for the world, regions and subregions, and economic groupings of countries.2
Calculation of indicators

The technical notes indicate whether the indicator was calculated by ESCAP or obtained from another international agency.

The following types of calculations were performed in deriving indicator values. They are listed here in the order in which they are typically performed:

  • imputation of land area;
  • growth rates;
  • ratios (such as per capita figures);
  • percentages (such as percentage of GDP);
  • constant price values using implicit price deflators; and
  • period averages (such as five year averages).

Imputation of land area

A number of environment indicators are expressed as a percentage of total land area. To permit calculation and comparison of such indicators across countries and years, ESCAP completes the information for years where the source – the FAO land area database – does not contain a value. Land area is imputed using the value from the previous or following year. The margin of error is small because the land area of a country normally remains constant. If there is evidence that country borders have changed, the imputation is not completed. Calculations involving imputed land area are included in this Yearbook, although land areas themselves are only published online.

Ratios and percentages

Ratios are only displayed if data for the numerator is non-missing; and data for the denominator is non-missing and non-zero. Gender parity ratios, per capita figures and mortality rates are a few examples of ratios calculated by ESCAP.

Indicators expressed as percentages (such as percentage of GDP, land area or population) are calculated following the same methodology as ratios.

For the present Yearbook, per capita figures were calculated using the United Nations population database World Population Prospects: The 2010 Revision (WPP2010) and GDP figures were calculated using the United Nations Statistical Division National Accounts Main Aggregates Database (NAMAD).

Growth rates

Growth rates are presented as percentage change per annum.

Where annual data are measured in absolute terms, the rates of change from one year to the next are calculated as proportional changes from the earlier period. Rates of change over several years are calculated using the geometric growth model. The geometric growth rate uses discrete compounding.

Where the underlying data are measured in levels, the formula for the average annual percentage change in indicator P over n periods is

r = [(Pn /P1)1/n – 1] • 100.

Constant price values using implicit price deflators

Implicit price deflators with a 2005 base, from NAMAD, are used in converting current price data to constant 2005 prices, as follows:

Constant price values using implicit price deflators

Where is the 2005 constant price value for year t; Ct is the current price value for year t; and It 2005 is the 2005 implicit price deflator for year t.

Period averages

In the Yearbook period averages, such as five-year averages, are calculated either as (a) a simple arithmetic mean, if the period average is based on an indicator from an international data source that is not ESCAP; or (b) the sum of the numerator (for the ratio or percentage) divided by the sum of the denominator over the period. Data are not imputed for the purpose of calculating period averages.

Country names and groupings

“Asia and the Pacific” in this Yearbook refers to the 58 regional members and associate members of the Economic and Social Commission for Asia and the Pacific. The 58 regional members and associate members are referred to as “countries” throughout the Yearbook even though some territories which are not countries are included. Some countries referred to by a shortened version of their official name in tables and charts, as indicated in brackets in the listing below.

Asia-Pacific subregions

By geographic subregion, the countries and areas of Asia and the Pacific are:

East and North-East Asia (ENEA): China; Democratic People’s Republic of Korea (DPR Korea); Hong Kong, China; Japan; Macao, China; Mongolia; Republic of Korea.

South-East Asia (SEA): Brunei Darussalam; Cambodia; Indonesia; Lao People’s Democratic Republic (Lao PDR); Malaysia; Myanmar; the Philippines; Singapore; Thailand; Timor-Leste; Viet Nam.

South and South-West Asia (SSWA): Afghanistan; Bangladesh; Bhutan; India; the Islamic Republic of Iran (Iran (Islamic Rep. of )); Maldives; Nepal; Pakistan; Sri Lanka; Turkey.

North and Central Asia (NCA): Armenia; Azerbaijan; Georgia; Kazakhstan; Kyrgyzstan; the Russian Federation; Tajikistan; Turkmenistan; Uzbekistan.

Pacific: American Samoa; Australia; Cook Islands; Fiji; French Polynesia; Guam; Kiribati; Marshall Islands; Micronesia, Federated States of (Micronesia (F.S.)); Nauru; New Caledonia; New Zealand; Niue; Northern Mariana Islands (Northern Mariana Is.); Palau; Papua New Guinea; Samoa; Solomon Islands; Tonga; Tuvalu; Vanuatu.

Economic groupings

The classification of countries into income groups is from the World Bank. The World Bank divides countries according to their 2009 gross national income (GNI) per capita, calculated using the World Bank Atlas method. Group classifications are: low income ($995 or less); lower-middle income ($996-3,945); uppermiddle income ($3,946-12,195); and high income ($12,196 or more).

Low-income countries: Afghanistan; Bangladesh; Cambodia; Democratic People’s Republic of Korea; Kyrgyzstan; Lao People’s Democratic Republic; Myanmar; Nepal; Tajikistan; Solomon Islands.

Lower middle-income countries: Armenia; Bhutan; China; Georgia; India; Indonesia; Kiribati; Maldives; Marshall Islands; Micronesia (Federated States of); Mongolia; Pakistan; Papua New Guinea; the Philippines; Samoa; Sri Lanka; Thailand; Timor-Leste; Tonga; Turkmenistan; Tuvalu; Uzbekistan; Vanuatu; Viet Nam.

Upper middle-income countries: American Samoa; Azerbaijan; Fiji; the Islamic Republic of Iran; Kazakhstan; Malaysia; Palau; the Russian Federation; Turkey. High-income countries: Australia; Brunei Darussalam; French Polynesia; Guam; Hong Kong, China; Japan; Macao, China; New Caledonia; New Zealand; Northern Mariana Islands; Republic of Korea; Singapore.

Other Asia-Pacific groupings

Within Asia and the Pacific, the following groupings are also used:

Landlocked developing countries: (LLDC): Afghanistan; Armenia; Azerbaijan; Bhutan; Kazakhstan; Kyrgyzstan; Lao People’s Democratic Republic; Mongolia; Nepal; Tajikistan; Turkmenistan; Uzbekistan.

Least developed countries (LDC): Afghanistan; Bangladesh; Bhutan; Cambodia; Kiribati; Lao People’s Democratic Republic; Maldives; Myanmar; Nepal; Samoa; Solomon Islands; Timor-Leste; Tuvalu; Vanuatu.

Pacific island developing economies (PIDE): American Samoa; Cook Islands; Fiji; French Polynesia; Guam; Kiribati; Marshall Islands; Micronesia (Federated States of); Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Samoa; Solomon Islands; Tonga; Tuvalu; Vanuatu.

Association of Southeast Asian Nations (ASEAN): Brunei Darussalam; Cambodia; Indonesia; Lao People’s Democratic Republic; Malaysia; Myanmar; the Philippines; Singapore; Thailand; Viet Nam.

Economic Cooperation Organization (ECO): Afghanistan; Azerbaijan; the Islamic Republic of Iran; Kazakhstan; Kyrgyzstan; Pakistan; Tajikistan; Turkey; Turkmenistan; Uzbekistan.

South Asian Association for Regional Cooperation (SAARC): Afghanistan; Bangladesh; Bhutan; India; Maldives; Nepal; Pakistan; Sri Lanka.

Central Asia (C Asia): Armenia; Azerbaijan; Georgia; Kazakhstan; Kyrgyzstan; Tajikistan; Turkmenistan; Uzbekistan.

Regions of the world

For comparative purposes, aggregates are also presented for the world’s major regions, as follows:

Africa: Algeria; Angola; Benin; Botswana; Burkina Faso; Burundi; Cameroon; Cape Verde; Central African; Republic; Chad; Comoros; Congo; Côte d’Ivoire; Democratic Republic of the Congo; Djibouti; Egypt; Equatorial Guinea; Eritrea; Ethiopia; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Kenya; Lesotho; Liberia; Libyan Arab Jamahiriya; Madagascar; Malawi; Mali; Mauritania; Mauritius; Mayotte (France); Morocco; Mozambique; Namibia; Niger; Nigeria; Réunion (France); Rwanda; Saint Helena; São Tomé and Príncipe; Senegal; Seychelles; Sierra Leone; Somalia; South Africa; Sudan; Swaziland; Tanzania (United Republic of ); Togo; Tunisia; Uganda; Western Sahara; Zambia; Zimbabwe.

Asia-Pacific region: As described above

Latin America and Caribbean (LAC): Anguilla; Antigua and Barbuda; Argentina; Aruba; Bahamas; Barbados; Belize; Bolivia; Brazil; British Virgin Islands; Cayman Islands; Chile; Colombia; Costa Rica; Cuba; Dominica; Dominican Republic; Ecuador; El Salvador; Falkland Islands (Malvinas); French Guiana; Grenada; Guadeloupe; Guatemala; Guyana; Haiti; Honduras; Jamaica; Martinique; Mexico; Montserrat; Netherlands Antilles; Nicaragua; Panama; Paraguay; Peru; Puerto Rico; Saint Kitts and Nevis; Saint Lucia; Saint Vincent and the Grenadines; Suriname; Trinidad and Tobago; Turks and Caicos Islands; United States Virgin Islands; Uruguay; Venezuela (Bolivarian Republic of ).

North America (N Am): Bermuda; Canada; Greenland; Saint Pierre and Miquelon; United States.

Europe: Albania; Andorra; Austria; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; Channel Islands; Croatia; Czech Republic; Denmark; Estonia; Faeroe Islands; Finland; France; Germany; Gibraltar; Greece; Guernsey; Holy See; Hungary; Iceland; Ireland; Isle of Man; Italy; Jersey; Kosovo; Latvia; Liechtenstein; Lithuania; Luxembourg; Malta; Monaco; Montenegro; Netherlands; Norway; Poland; Portugal; Republic of Moldova; Romania; San Marino; Serbia; Slovakia; Slovenia; Spain; Svalbard and Jan Mayen Islands; Sweden; Switzerland; [the former] Yugoslav Republic of Macedonia; Ukraine; United Kingdom of Great Britain and Northern Ireland.

Other countries or areas: Bahrain; Cyprus; Iraq; Israel; Jordan; Kuwait; Lebanon; Norfolk Island; Occupied Palestinian Territories; Oman; Pitcairn; Qatar; Saudi Arabia; Syrian Arab Republic; Taiwan Province of China; Tokelau; United Arab Emirates; Wallis and Futuna Islands; Yemen.

Aggregation methods

Aggregate values are presented for subregional, regional, special economic and world groupings (as per the groupings above). World aggregates are taken directly from the data source when available. Subregional, regional, and economic groupings are calculated using ESCAP country groupings to ensure consistency throughout the Yearbook.

Some aggregates have been calculated by agencies responsible for the compilation and production of indicators under their area of expertise. These include some education indicators (aggregates calculated by UIS/UNESCO), some employment indicators (aggregates calculated by ILO), and all tourism indicators (aggregates calculated by UNWTO). In such cases, the methodology may differ from the methods described below, additional information can be obtained from the respective agencies. When aggregates are not calculated by ESCAP, the source is indicated in the technical notes.

The calculation of aggregates involves three steps: (1) determining whether “enough” data are available (at least two thirds of the population for social indicators, and at least two thirds of GDP for economic indicators); (2) imputing missing values (not employed for all indicators); and (3) calculating the aggregate sum or weighted average.

For Millennium Development Goals (MDG) indicators, in addition to aggregate values, the aggregate affected populations are also calculated following the methodology described in the Asia-Pacific MDG Report 2011/12 (http://

1: Determining whether “enough” data are available: the “two-thirds test”

To ensure that aggregates are representative, an aggregate is only calculated for a given year if the population (for social indicators) or the GDP (for economic indicators) of countries with available values for that year covers more than two thirds of the total population or GDP of the group of countries under consideration. As population data (including 2010 data) and GDP data (up to 2009) are available for all United Nations member states, the test for two thirds of the total population or GDP can be applied to all indicators in the Yearbook.

For data not expected to be available for every country (such as official development assistance [ODA], which is only received by specific developing countries), a slight modification of the above methodology is used. The two-thirds test is applied to the group of countries for which data are expected to be non-missing (such as recurrent ODA recipients).

2: Imputing missing values

If an indicator has passed the two-thirds test, but values are missing for some countries, then the missing country data may be imputed to present a more realistic aggregate (the technical notes specifies if missing values are imputed or not). Imputed values are only used in the calculation of aggregates; they are not published online or in print (with the exception of land area). Two methodologies are applied for imputations: one for MDG indicators, and another for non-MDG indicators, as described below.

2a: Imputation methods: MDG indicators

For MDG indicators, missing values are imputed on the basis of the trend; however, if progress is negative, the latest available value is carried forward for future values. For a full description of the methods, see the Asia-Pacific MDG Report 2011/12 (

2b: Imputation methods: non-MDG indicators

For non-MDG indicators, missing country values are imputed using the following methodology.

(1) If values are available for both a preceding and a following year, missing values are imputed using linear interpolation
(2) If a preceding value is available but not a following value, the most recent year of data is carried forward.
(3) If a following value is available but not a preceding value, the most recent year of data is carried backward.
(4) For countries with only one data point for the whole period, that value is used for all missing years.
(5) If no data exist for any year for a country, no value is imputed. (Information from other countries is never used in imputing missing values.)

3: Calculating aggregate sums and weighted averages

Two types of aggregates are used in the Yearbook: straight sums and weighted averages. For calculated indicators, aggregates are based on the original indicator (as opposed to calculating the aggregate based on other aggregates).

If the aggregate is a sum, then the aggregate data are derived by finding the sum total of all country-level data within each aggregation group.

If the aggregate is a weighted average, then the aggregate data are derived by finding the weighted average of all data within each aggregation group. Weights have been determined by ESCAP for each indicator and are included in the technical notes. The weights are not imputed; if the weight is missing, then the country-level data for that country are not included. For ratios, denominators are used as weights.

1 The following section on calculation of indicators describes the methodology in full.

2 Not all aggregates are calculated by ESCAP; the following section on aggregation methods provides full details on aggregation methods.

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