The question of how many people have ever lived on Earth is a perennial one among information calls to PRB. One reason the question keeps coming up is that somewhere, at some time back in the 1970s, a now-forgotten writer made the statement that 75 percent of the people who had ever been born were alive at that moment.
If this estimate were true, it would indeed make an impressive case for the rapid pace of population growth in this century. But if we judge the idea that three-fourths of people who ever lived are alive today to be a ridiculous statement, have demographers come up with a better estimate? What might be a reasonable estimate of the actual percentage?
Any such exercise can be only a highly speculative enterprise, to be undertaken with far less seriousness than most demographic inquiries. Nonetheless, it is a somewhat intriguing idea that can be approached on at least a semi-scientific basis.
Still, with some speculation concerning prehistoric populations, we can at least approach a guesstimate of this elusive number.
