Africa will be home to a third of the world’s population by 2100, a bulge that can be taken as a chance to boost economy given the larger young workforce, instead of a threat, according to The Economist. Africa and Asia will account for most of the world’s population growth in the coming decades and will be home to eight of the 10 most populous countries by 2050. By 2024, India is expected to overtake China as the world’s most populous country. And Nigeria will boast the world’s fastest growing population and overtake the United States as the world’s third most-populous country by 2050. The world’s population, which has doubled in less than four decades, is expected to increase by 1 bn in 2030 to reach 8.7 bn.

Shrinking populations: Japan’s 127 mn population is forecast to shrink by about one third over the next 50 years as more people die than are born. But the fastest-shrinking populations will be in Eastern Europe, including Romania, Serbia, Poland, Ukraine and Bulgaria, due to migration, high mortality rates and low birth rates (watch: runtime: 2:46).