Data Sources

A description of the empirical data used and the methods applied in revising past estimates of population and components of demographic change (fertility, child, adult and overall mortality, international migration) is available here for each country or area for the period 1950 to 2021. For the countries with less than 1,000 inhabitants in 2021, only the data sources for total population are made available.

Select below a country or area to see the respective information, or download the whole set of metadata in PDF format for all countries or areas or a tabular version for each demographic component under Documentation.

Nepal

Population: Total population and distribution by age and sex estimated to be consistent with the population by age and sex of the (a) 1952-1954, 1961, 1971, 1981, 1991, 2001, 2011 censuses; (b) adjusted for under/over count; (c) adjusted for age heaping; (d) adjusted for under enumeration of children under age 15; (e) 1985-1986 FFPS survey estimates; (f) official estimates through 2021; (g) only total population for 2021 Census; and with estimates of the subsequent trends in fertility, mortality and international migration.

Fertility: Total fertility rate and age pattern of fertility based on: (a) official estimates of age-specific fertility rates through 2011; (b) birth-histories data from the 1985-1986 FFPS and 1996, 2001, 2006, 2011, 2016 DHS and 2014, 2019 MICS; (c) births in the household in the preceding 12 (or 24) months classified by age of mother from the 1961, 1971, 1981, 2001, 2011 censuses and 1974-1978, 1986-1987 DSS and 1976 WFS and 1981 CPS and 1991-1992 FFPHS; (d) adjusted fertility using Brass P/F ratio method (or variants) with data on children ever born and births in the preceding 12 (or 24/36) months, both classified by age of mother, from the 1986-1987 DSS and 1995-1996, 2003-2004 LSMS; (e) adjusted fertility using Arriaga modified P/F ratio method with data on children ever born and births in the preceding 12 (or 24/36) months, both classified by age of mother, from the 1995-1996 LSMS and 2011 Census; (f) adjusted fertility using synthetic relational Gompertz model with data on children ever born and births in the preceding 12 (or 24/36) months, both classified by age of mother, from the 1961, 1971, 1981 censuses and 1976 WFS and 1986-1987 DSS and 1991-1992 FFPHS; (g) indirect estimates obtained from the application of the reverse survival method to the 1952-1954, 1961, 1971, 1981, 1991 censuses and 1985-1986 FFPS; (h) indirect estimates obtained from the application of the own-children method of fertility estimation to the 1976 WFS and 1991-1992 FFPHS and 1995-1996 LSMS; (i) cohort-completed fertility backdated by the mean age of childbearing from the 1961, 1971, 2001, 2011 censuses and 1995-1996, 2003-2004, 2010-2011 LSMS and 1996, 2001, 2006, 2011, 2016 DHS and 2014, 2019 MICS.  In addition, the (a) birth-histories data from the 1976 WFS; (b) adjusted fertility using Brass P/F ratio method (or variants) with data on children ever born and births in the preceding 12 (or 24/36) months, both classified by age of mother, from the 2010-2011 LSMS; (c) indirect estimates obtained from the application of the reverse survival method to the 1956-2013 Education Stats and 2001, 2011 censuses; (d) cohort-completed fertility backdated by the mean age of childbearing from the 1976 WFS and 1981, 1991 censuses and 1991-1992 FFPHS have been considered.

Child Mortality: Under-five mortality based on: (a) registered infant and child deaths through 1981; (b) direct estimates from births and deaths under-five calculated from full birth histories data from the 1976 WFS and 1991-1992 FFPHS and 1996, 2001, 2006, 2011, 2016 DHS and 2014, 2019 MICS; (c) recent household deaths from the 2011 Census; (d) International estimates used up to 2021.  In addition, the (a) direct estimates from births and deaths under-five calculated from full birth histories data from the 1974-1978 DSS and 1981 CPS and 1985-1986 FFPS; (b) indirect estimates from data on children ever born and surviving from the 1971, 1981, 1991, 2001 censuses; (c) recent household deaths from the 1981, 1991, 2001 censuses have been considered.

Overall Mortality: Life expectancy at birth and age pattern of mortality based on: estimates using CD West model life tables and estimates of under-five mortality (5q0), and adult mortality (45q15).

Adult and Old Age Mortality: Estimates derived from: (a) recent household deaths data by age and sex from the 1981, 1991, 2011 censuses; (b) recent household deaths adjusted at adult ages for underregistration using death distribution methods; (c) siblings deaths from the 1996, 2006, 2016 DHS; (d) estimates of under-five, adult and old age mortality.  In addition, the recent household deaths data by age and sex from the 2001 Census have been considered.

Migration: International migration based on: (a) information on foreign-born populations from censuses and registers from major countries of destination; (b) information on the number of workers receiving clearances to work abroad; (c) estimates derived as the differences between overall population growth and natural increase; (d) UNHCR statistics on the number of refugees in the main countries of asylum.

Disclaimer: This web site contains data tables, figures, maps, analyses and technical notes from the current revision of the World Population Prospects. These documents do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.