Fertility

Being 30 then and now

In the mid-to-late-20th century, the American economy and culture were ripe for 30-year-old men, who — more than European and Japanese — typically landed well-paid careers, bought homes, and supported large families. But since then, getting ahead has become much harder.

Data: College attendance, median income, and home ownership from U.S. Census Bureau; cost of tuition from CollegeBoard; median debt from "The Great American Debt Boom, 1948-2013" by Alina Bartscher, Moritz Kuhn, Moritz Schularick and Ulrike I. Steins; marriage figures from a Pew Research Center analysis of the 1960-2000 decennial censuses and 2010 and 2016 American Community Survey (IPUMS). Note: All dollars are inflation-adjusted to 2016. Chart: Harry Stevens/Axios

The dangers of Nigeria's population explosion

A group of Nigerian young men standing in a market
In a Lagos market. Photo: Stefan Heunis/AFP via Getty Images

Nigeria is on track to have the third-highest population in the world, behind only India and China, according to the UN, a change that could reverberate globally since it's also likely to remain poor.

Why it matters: With more people will come more health risks, a need for more food from already-stressed agricultural land — and the potential for regional and global instability as poor Nigerians along with other Africans seek to migrate for a better life.