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UN DESA | DPAD | Development Policy Analysis Division

The criteria for identifying least developed countries

Definitions and main data sources

Updated September 2014
Disponibles en français: Définitions et sources principales des données

Adult literacy rate

The indicator measures the number of literate persons aged fifteen and above expressed as a percentage of the total population in that age group. A person is considered literate if he/she can read and write, with understanding, a simple statement related to his/her daily life. The indicator provides information on the size of the bases available for enlarging the trained and skilled human resources needed for development.

Gross secondary school enrolment ratio

The indicator measures the number of pupils enrolled in secondary schools, regardless of age, expressed as a percentage of the population in the theoretical age group for the same level of education. It provides information on the share of population with a level skills deemed to be necessary for significant developmental progress.

Gross national income (GNI) per capita

GNI per capita provides information on the income status of a country. GNI is equal to the gross domestic product (GDP) less primary incomes payable to non- resident units plus primary incomes receivable from non-resident units. The GNI measure used by the CDP is expressed in current United States Dollars. Values are expressed in current United States dollars, calculated according to the World Bank Atlas method and reflect an unweighted average of three years (2011, 2012 and 2013 in the case of the 2015 triennial review).

  • The indicator is calculated by the United Nations Statistics Division on basis of its National Account Main Aggregates Database and data of the relative weights of currencies in the Special Drawing Rights (SDR) by the International Monetary Fund.

Instability of agricultural production

The indicator measures the annual fluctuations of total agricultural production expressed in real terms, which reflect, among other things, the vulnerability of countries to natural shocks, in particular impacts of droughts and disturbances in rainfall patterns. Agricultural production covers all crops and livestock produced in a country.  The indicator is calculated by estimating the trend of agricultural production by linear regression (mixed-trend regression) and using the standard deviation of production around its trend as instability measure.

Instability of exports of goods and services

The indicator measures the instability of the capacity of countries to import goods and services from current export earnings, a major source of production and employment in many developing countries. The indicator is calculated by estimating the trend of export earnings by linear regression (mixed-trend regression) and using the standard deviation of exports around their trend as instability measure.

Merchandise export concentration

The indicator measures the sectoral concentration of a country's exports, indicating to which extent exports are dispersed across different economic activities. The indicator is expressed as a Herfindahl-Hirschmann index, defined as the sum of the percentages of the shares of each commodity (at the three-digit SITC product category) as a proportion of total exports. It is normalized so that it can vary between 0 and 1 (in case only one good is exported). Due to data constraints, it currently comprises only goods, but not services. The indicator provides information on the exposure to trade shocks resulting from a concentrated export structure.

  • The indicator is regularly reported by the United Nations Conference on Trade and Development through its data dissemination system UNCTADstat .

Percentage of population undernourished

The indicator provides information on the prevalence of undernourishment in the total population. It shows the proportion of the population whose dietary consumption continuously falls below an established minimum dietary energy requirement for maintaining a healthy life and carrying out light physical activity. Undernourishment compromises the health status and educational achievement and has an important negative impact on productivity.


The indicator measures the de-facto population of a country size at the mid-point (1 July) of the year indicated. The size of the population can be used as a proxy of a country's exposure to a variety of shocks, since small countries have fewer possibilities for economic diversification. Moreover, most small countries are highly exposed to natural shocks, which often affect the whole country.


The indicator measures the trade-weighted minimum distance for a country to reach a significant fraction (i.e., 50 per cent) of the world market. In order to account for relatively higher transportation costs and related handicaps of landlocked developing countries, a constant factor is added to the trade-weighted minimum distance for these countries. Remoteness reflects high transportation costs and limits the possibility for economic diversification, thereby reducing the ability of countries to respond to trade shocks.

A more detailed explanation of the remoteness indicator and its calculation can be found in “Measuring remoteness for the identification of LDCs” by the CDP Secretariat.

Share of agriculture, forestry and fisheries in GDP

The indicator is defined as the share of gross value added in the agriculture, forestry and fishery sectors (Categories A and B in the ISIC classification rev. 3 and 3.1) in the gross domestic product (GDP) of a country. The indicator provides information on the exposure of countries caused by their economic structure, because agriculture, fisheries and forestry are particularly subject to natural and economic shocks.

Share of population in low elevated coastal zones

The indicator measures the share of the population in a country that lives in low elevated coastal zones, defined as areas contiguous to the coast below a certain elevation threshold. Currently, an elevation threshold of 5 meters is used. The indicator intends to capture vulnerability to coastal impacts (including sea level rise and storm surges) associated with climate change.

Under five mortality rate

The indicator expresses the probability of dying between birth and age five. It is expressed as deaths per 1,000 births. Under five mortality rate provides comprehensive information on the health impacts of social, economic and environmental conditions in a country. It is seen as more reliable than alternative indicator such as life expectancy, in particular in least developed countries.

Victims of natural disasters

The indicator measures the share of the population that has been a victim of natural disasters. Victims of natural disasters are defined as people killed or affected (i.e., people requiring immediate food, water, shelter, sanitation or medical assistance). It covers weather and climate-related disasters (such as floods, landslides, storms, droughts and extreme temperatures) as well as geo-physical disasters (such as earthquakes or volcanoes). The indicator reflects vulnerability to natural shocks, in particular the human impact of natural disasters associated with these shocks.