Who can predict what the world will look like in 55 years? If there's one group willing to go boldly forth into the statistical unknown, it's demographers. Armed with regressions, piles of data, and many a chart, the researchers at Pew have projected that after 2070, the world's Muslims will outnumber the world's Christians.
"In the process of gathering all the data to think about the future of religion in the world, we learn about differences between religious groups that exist today," said Conrad Hackett, the lead demographer on the massive new report. Researchers looked at census data, surveys, and population registers for 234 countries to estimate the future sizes of the world's religious groups. They advise readers to interpret the data with caution—there's a page-long section called "disclaimers"—but offer insight into what demographers know best: how births, deaths, and migration define peoples over time.
The results are fascinating. The Muslim population, for example, is expected to grow twice as fast as the rest of the world's population between now and 2050, largely because Muslims tend to be young and have high fertility rates. A majority of Muslims will still live in Asia and the Pacific region, as they do now (even though Islam is the predominant religion of the Middle East, only one in five Muslims live there). While their life expectancy will likely rise over the next four decades, on average, Muslims will still die younger than members of any other religion, including folk religions. Jews, on the other hand, will live the longest; in 2050, the group's life expectancy will be 85, compared with 75 for Muslims. This is partly because the Jewish population is so concentrated, Hackett said: Roughly 80 percent of Jews live in Israel or the United States, both highly developed countries.