Sub-Saharan Africa's population dynamics will remain favorable in the context of strong labor force growth and declining dependency ratios, and countries that manage to pursue growth-oriented economic policies and maintain political stability will emerge as high-growth economies. Sub-Saharan Africa is the world's demographically most dynamic region, which is an important structural factor underpinning the region's significant (if mostly unrealized) economic potential, as well as its susceptibility to political instability. While most of the world's advanced countries are stagnating demographically, sub-Saharan Africa continues to experience rapid population growth in the context of high fertility rates and declining mortality. 

• The median age of advanced economies is somewhere between 40 and 50 (for example, the median age in the United States is 39, and in Japan it is 49). The median age of most sub-Saharan African countries, by contrast, is only 25. 
• Fertility is an estimate of the number of births per woman in a specific population. According to the United Nations, the fertility rate in West Africa and Central Africa is 4.8 children per woman; in Eastern Africa and Southern Africa, it is 4.1 children per woman. Among sub-Saharan African countries, Niger has by far the highest fertility rate, with 6.6 children per woman, while Cape Verde has the lowest rate with 1.9 children per woman. For comparison, the average fertility rate in Asia-Pacific and Latin American countries is 1.9 and 1.8, respectively. 
• Of the top 40 countries with the highest fertility rate in the world, 36 are located in sub-Saharan Africa (the other four are three Pacific Island countries and Afghanistan). 

In the coming decades, sub-Saharan Africa's demographic dynamics will remain broadly favorable compared with the rest of the world due to a growing labor force. The demographic trends in sub-Saharan Africa, where the working-age population will expand significantly in the decades ahead, stand in sharp contrast with those in advanced and emerging economies. In countries like China and Japan, the working-age population has already peaked, which means that the potential and actual labor force has already begun to decline, weighing on their medium- to long-term economic growth outlook. In many Western European countries, the working-age population is stagnating, with net immigration being the only reason it is not in decline. In Eastern Europe and East Asia, the working-age population is shrinking and will continue to shrink. However, in sub-Saharan Africa, current demographic projections show that the working-age population will expand rapidly in the coming decades. Historically, demographic projections have tended to underestimate the rapid decline in fertility brought on by economic development, particularly in lower and upper-middle-income countries. It is thus possible that both fertility and dependency ratios will also decline more rapidly in sub-Saharan Africa than currently anticipated, particularly in countries experiencing rapid economic development (which lessens economic needs to have a large number of children) and improving education levels (which makes women postpone childbirth and have fewer children). Should fertility decline faster in sub-Saharan Africa, translating into improving dependency ratios (or the number of people not of working age relative to the number of working age), the economic outlook would improve further. 

• In Africa, the population is expected to grow by 1.7% per year between 2025 and 2050. In Asia, Europe and the Americas, population change will be minimal, ranging from -0.3% per year in Europe to 0.2% in Asia, including India. Africa's population will make up 23% of the world's population by 2050, up from 16% in 2023.
• A declining dependency ratio increases the number of people working relative to ''dependents,'' such as the elderly and children, thus allowing for increased savings rates, higher investment and faster economic growth. Sub-Saharan Africa's dependency ratio remains very high, but it has slowly begun to decline in recent years. Dependency ratios have long bottomed out in most demographically advanced economies, and they will do so in most emerging economies in 2030-40. By comparison, sub-Saharan African dependency ratios are projected to bottom out in 2070-80, assuming that current projections are correct.

Despite a promising demographic outlook, only the countries that maintain political stability and pursue sound economic policies conducive to the exploitation of the so-called demographic dividend will be able to realize it. The scope of these challenges varies significantly from one country to another due to factors such as geography and history. Countries enjoying stable maritime access are set to enjoy lower transportation costs than their landlocked peers, thanks to having easy access to global shipping routes. Moreover, countries with relatively lower ethnic tensions, such as Senegal and Tanzania, and a stronger history of abiding by the rule of law, such as Botswana, will likely face less frequent bouts of political instability owing to smooth transitions of power within their political leadership. Low per capita income and a low capital stock provide conditions for accelerated growth, provided the governments manage to implement forward-looking, growth-oriented policies that leverage the favorable demographic momentum. 

• Almost half of the world's 20 fastest-growing economies are located in sub-Saharan Africa. This includes Ethiopia, Rwanda and Tanzania, which all registered real GDP growth of more than 6% per year over the past decade. 
• While sub-Saharan Africa represents a large share of the world's fastest-growing economies, it is also home to some of the world's worst-performing economies. Sudan, the Central African Republic, the Republic of Congo, and Equatorial Guinea all registered negative real economic growth over the past decade, which in the context of demographic growth means significantly shrinking per capita income. These countries' poor performance was mostly due to political instability and civil strife, or a sharp collapse of the natural resource sector.
• Of the 50 countries in sub-Saharan Africa, 44 have a per capita income of less than $10,000 on a purchasing-power-parity basis. By comparison, all North African countries have per capita incomes exceeding $10,000. 

Demographic change is slow, but it is a potentially important driver affecting both economic growth and political instability. Rapid population growth without political instability is possible, depending on factors such as the degree of government control and socio-economic or socio-ethnic cleavages. Nonetheless, a quickly growing population — and particularly a rapid increase in the young adult population — will create significant political challenges. The economy needs to provide jobs for the expanding labor force, which proves challenging in many countries in sub-Saharan Africa, where governments pursue economic policies geared toward maintaining and/or expanding their patronage system. Sub-Saharan countries that manage to implement far-sighted policies and maintain requisite political stability will likely do well in the coming years. Barring a rapid upsurge in domestic instability, Tanzania, Uganda and Ethiopia appear particularly well-positioned to leverage their growing populations, as do coastal West African countries located along the Lagos-Abidjan corridor (except Nigeria, which will continue to struggle to boost economic growth due to internal security challenges and its heavy reliance on oil production). By contrast, countries already afflicted by significant domestic and civil strife, such as Sudan, Somalia and the Democratic Republic of the Congo, will find it difficult to exploit the favorable demographics characterizing the region. 

• According to current trends and projections, the populations of Nigeria, Ethiopia, the Democratic Republic of Congo and Tanzania will nearly double by 2050.