One Child by Mei Fong

years before a group of reformers would emerge, academics who would try to use the tools of logic and research to undo the one-child policy’s Gordian knot.
     
     
    IV
     
    Looking back, it seems amazing how confident China’s rocketmen were in their projections of population growth, refusing to factor in how human behavior or technology might change their projections. They appeared utterly sure of the correctness of their solution.
    This Masters of the Universe mindset is clear in a 1988 book Song and Yu published explaining their theories. Wrote the authors:
     
Since human beings appeared in the world millions of years ago, they have been battling with Nature. Now they have finally conquered it by their wisdom and social strength, and won brilliant victories.
We have placed the whole vegetable kingdom under our control. . . . We have become the rulers of the entire animal kingdom and conquered all kinds of ferocious beasts that once killed or injured large numbers of our ancestors. . . . Now we have got our revenge on them, using their lives to repay the blood debts they owe us from history. . . .
We have tamed the rivers and controlled lightning . . . roam in outer space, land on the Moon, and send messengers to Venus, Mars and other planets. . . .
In short, we have been the victors, we have mastered the world, we have conquered outer space and we have won freedom.
     
    The rocketmen calculated that China’s optimal population a century hence would be about 700 million people, but they based their calculations on a variety of questionable assumptions.For example, they presupposed that the ideal Chinese diet would involve Western-style protein consumption. There was no way China’s agricultural production could ramp up to allow for this sudden change, so, to meet this goal, the population would have to be drastically reduced.The whole project entailed making “countless heroic assumptions” on the basis of “little more than educated guesswork,” said Greenhalgh.
    The rocketmen’s calculations did not factor in how quickly fertility would decrease as modern educated Chinese women opted for fewer children.By 2010, census results showed that averageannual population growth had been at half the rate of the previous decade.
    In the course of many conversations with demographers, I learned that predicting population growth is a tricky business. Forecasts are reasonably accurate only up to a twenty- to thirty-year time frame. Demographers base their predictions on three factors: how many people are born, how long people live, and how they move around.
    Out of these three, only one—mortality rates—can be predicted fairly accurately today.Migration and fertility patterns have been much harder to foresee, because they are deeply intertwined with individual decision making and agency.“There is no good theory to explain, much less predict, why fertility rates change over time,” said population scholar Matthew Connelly.By the end of this century, the world’s population could be anywhere between 8 billion and 13 billion, depending on which demographic projections you choose to believe.The difference between the two numbers is as many people as there were on Earth in the 1950s.Demographers know the world’s population in 2030, but for 2050, “we are in uncharted waters,” and for 2100—“well, science fiction,” said demographer Nicholas Eberstadt.
    Olsder, now a retired professor, says his original problem was just a “wonderful kind of mathematical exercise.The social, economic aspects were not factored in.
    “I don’t know, we lived in a university, in a tenured position, and I was trying to keep myself fresh in a math way. It was a competition with colleagues to show off, to show you were active. I never anticipated this long chain of events,” he said.
    The Club of Rome’s doomsday predictions did not come to pass, but “for many people it was an awakening, to be careful with Earth and our