The world population is projected to increase from 7.7 billion in 2019 to 8.5 billion in 2030 (10% growth), 9.7 billion in 2050 (26%), and 10.9 billion in 2100 (42%). Sub-Saharan Africa's population will double (99%) by 2050, while projected population growth rates (2019-2050) for other regions are 56% in Oceania (excluding Australia and New Zealand), 46% in North Africa and West Asia, 28 % in Australia and New Zealand, 25% in Central and South Asia, 18% in Latin America and the Caribbean, 3% in East and Southeast Asia, and 2% in Europe and North America.

By 2050, more than half of the world's population growth is projected to be concentrated in nine countries: India, Nigeria, Pakistan, the Democratic Republic of the Congo, Ethiopia, Tanzania, Indonesia, Egypt, and the U.S. Around 2027, India is projected to surpass China to become the world's most populous country. India is expected to surpass China as the world's most populous country around 2027.

In many countries in sub-Saharan Africa and parts of Asia, Latin America and the Caribbean, economic growth will be driven by high growth rates in the working age population (25-64). To realize this "population dividend," governments should invest in the education and health of young people.

Globally, the number of children per woman is declining, although it remains high in some regions, such as sub-Saharan Africa (4.6).

The ratio of the working-age population (25-64) to the population aged 65 and over continues to decline worldwide, which could have a significant impact on public finances, the labor market and economic growth due to the need for spending on health care, pensions, social security and other programs. In particular, Japan, with its aging population, has the lowest ratio in the world at 1.8.

Several countries have begun to experience population decline due to low fertility rates and outmigration. China, for example, is projected to lose 31.4 million people between 2019 and 2050. Migration is another important demographic factor, with some countries experiencing outflows due to migration (Bangladesh, Nepal, Philippines) and civil war (Syria, Venezuela, Myanmar), while others are experiencing net inflows (Belarus, Estonia, Germany, Hungary, Italy, Japan, Russia, Serbia, Ukraine).