The milestone of 7 billion is marked by achievements, setbacks and paradoxes.While women are on average having fewer children than they were in the 1960s,our numbers continue to rise. Globally, people are younger and older than ever before. In some of the poorest countries, high fertility rates hamper development and perpetuate poverty, while in some of the richest countries, low fertility rates and too few people entering the job market are raising concerns.