I stand at my kitchen sink and watch Fred, my nine-year-old neighbor, play football in the backyard. He wears a helmet. He throws the ball. He catches the ball. He gets tackled. He exhibits fierce concentration as he plays all aspects of the game. In his head. Because, you see, Fred plays football by himself.

We live in the city. A dense neighborhood of 2- and 3- family houses with narrow driveways and tiny yards. I know many neighbors. But no other children close to Fred’s age. School age children in Cambridge are scarce (only 7% of the population), as children are in many American cities. A function of high-cost real estate, aging population, reduced birth-rates, and the societal perception that children should grow up in the country—or at least the suburbs.

From a city-planning perspective, the lack of children in Cambridge is considered a problem. Cambridge wants more children.

China’s population is plateauing, so China has abandoned it’s one-child policy. It wants more Chinese.

South Korea has the lowest birth-rate in the world. It wants more South Koreans.

Beleaguered groups often strive to have more children, for cultural continuation. Native Americans want more Native Americans. Mennonites want more Mennonites. Hasidic Jews want more Hasidic Jews. But these days, even bountiful populations seek to increase and multiply. “I want more babies in the United States of America,” shouted JD Vance in his first address as Vice-President.

Back in 1968, The Population Bomb proclaimed catastrophe for a planet with a mere 3.6 billion people. Yet, somehow, 58 years later we support more than twice that population, with proportionately better nutrition. Who knows the ultimate limit to human population the planet can sustain? Many already believe we’ve passed that dubious milestone. Others project it into some near or distant future. Most die-hard have-a-lot-of-baby people don’t even consider the issue.

What we do know is that at some point Mother Nature is going to stop accommodating these pesky humans tampering with her chosen rhythms and we’re going to get cut back to size. Should we try to curtail our own growth, or let the vicissitudes of nature deal with us how and when she likes?

In the aggregate, most people believe we should stabilize, if not reduce, the world’s population. They also believe that their particular tribe needs to grow. Therein lies the population conundrum. Reduce them; increase us.

The only form of population control found to be fully effective is actually quite simple. Educate girls. Across time and continents when women get educated, they gain agency, they gain a modicum of control, and they have fewer children. Neither draconian laws against child-bearing, nor incentives to increase it have altered that reality that educated women have fewer babies.

Of course, given the rightward political tack on planet Earth in 2026, only a contrarian would bet on more female empowerment. But that’s another subject.

In this moment, watching Fred literally contort himself to the ground as both running back and opposing safety, I can only imagine he wishes for another—maybe even two or three—football loving nine-year-old’s in the neighborhood.