It took more than 50,000 years for the world population to reach 1 billion people, but since 1960, we have added successive billions every one to two decades. The United Nations projects there will be 9 billion people on the planet by 2037. Demography is the study of life, death and everything we do in between. And throughout human history, we've seen plenty of population booms and busts. In this podcast, Harvard economist and demographer David Bloom, says public policy both shapes and responds to demographic trends. David Bloom's article, Population 2020, is published in the March issue of Finance & Development magazine. Read the TRANSCRIPT