The "bad news," said Last, is there are few examples of effective public policy to nudge fertility rates upward. Other countries that have tried to do so failed, the author of "What to Expect When No One's Expecting" said during an April 3 lecture at the Family Research Council.
The world population will peak before the end of this century and then quickly contract, Last predicted in a February opinion piece for the Los Angeles Times. This would be the first time this large and quick of a contraction took place since the Black Plague hit Europe in the Middle Ages.
At the Family Research Council event, Last cited some past efforts to boost fertility rates.
"The first attempt we see as pro-natalist public policy is actually from Caesar Augustus," Last said. "He passes in the late days of the Roman Empire, when they were having a fertility crunch, a bachelor tax -- to get unmarried young men to get married and start [having] kids. That did not work."
Another flawed attempt was Soviet dictator Joseph Stalin's medal incentive, he said.
"As Russians were getting wound up in World War II, he realized that they had a demographic problem and needed more babies, so he created the motherhood medal," said Last. "If a woman had six children, the first class medal; five, the second class. They would earn this wonderful little medal. You can buy them on eBay. They are about 12 dollars."
Last also talked about how the old views on American sexuality have been untethered from one another.
"Pre-1968 -- broadly speaking, you could not have sex without getting married. You could not have sex without having a child nine months later, and you couldn't have a kid out of wedlock. Certainly people did those things certainly on their own outside, but in broader society people didn't do that," Last said.
"The sexual revolution plays an enormous role on fertility," Last said.
In 1965, four percent of all births were to single mothers; today, it is 47 percent. It is not that America is unwilling to produce children; the problem is broken homes and the dropping fertility rate, Last said. America's ideal fertility rate is 2.5; it is currently 2.1.
"What has changed is not our conception of what the ideal family is but our ability to achieve it," said Last.
Steve Aden, senior counsel for Alliance Defending Freedom, asked if this problem was one of inherent selfishness among those who are able but choose not to have children.
Last said America's problem stems from "hyper-responsibility," not selfishness. He said those who want to move up economically usually choose to go to school longer, postponing the rates of marriage and childbirth.
"We don't need to browbeat people who do not want to have kids into wanting them," Last said.