Infographic map depicting population decline by country. This map is based on projected rate of change between 2020 and 2050 and using data from the United Nations. Many of the 20 fastest declining populations are located near Eastern Europe. Declining birth rates and large numbers of people emigrating are thought to be the main causes in these countries. Outside of Europe, Japan and Cuba will also experience G127population decline due to very low birth rates. Data from United Nations World Population Prospects 2022.