World Population Policies 2015 provides information on 197 countries, including all 193 Member States, two Observer States (the Holy See and the State of Palestine) and two non-member States (Cook Islands and Niue) of the United Nations.

Countries are grouped geographically into six regions: Africa; Asia; Europe; Latin America and the Caribbean; Northern America; and Oceania. These geographic regions are further divided into 21 subregions. In addition, countries are classified as belonging to either of the two general development groups: more developed regions and less developed regions.

Following common practice, the “more developed regions” comprise all countries in Europe and Northern America, plus Australia, New Zealand and Japan. The “less developed regions” comprise all countries in Africa, Asia (excluding Japan), Latin America and the Caribbean plus Melanesia, Micronesia and Polynesia.

The distinction between “more developed regions” and “less developed regions”, also referred to as “developed regions” and “developing regions”, derives from the sharp bifurcation of socioeconomic conditions that existed as recently as the nineteen-sixties but has since diminished as many countries of the less developed regions have undergone rapid development. The terms continue to be used because the distinction remains meaningful for some purposes despite its apparent limitations.

The current list of least developed countries (LDCs) includes 48 countries (34 in Africa, 9 in Asia, 4 in Oceania and 1 in Latin America and the Caribbean), as decided by the latest United Nations General Assembly resolution on this issue A/RES/70/78: Afghanistan, Angola, Bangladesh, Benin, Bhutan, Burkina Faso, Burundi, Cambodia, Central African Republic, Chad, Comoros, Democratic Republic of the Congo, Djibouti, Equatorial Guinea, Eritrea, Ethiopia, Gambia, Guinea, Guinea-Bissau, Haiti, Kiribati, Lao People’s Democratic Republic, Lesotho, Liberia, Madagascar, Malawi, Mali, Mauritania, Mozambique, Myanmar, Nepal, Niger, Rwanda, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, South Sudan, Sudan, Timor-Leste, Togo, Tuvalu, Uganda, United Republic of Tanzania, Vanuatu, Yemen and Zambia. Further information on LDC's can be found at: http://www.un.org/en/development/desa/policy/cdp/ldc/ldc_list.pdf.