Get ready for the Biden baby boom. The $1.9 trillion American Rescue Plan headed for passage in Congress includes an increase in the child tax credit, to $3,600 a year for children under six from the current $2,000. It would also make the credit fully refundable — and even distribute it in advance in monthly checks or electronic payments.

Whether this will be a disaster or a godsend is an open question. If the payments last for longer than the single year authorized by the Rescue Plan, they have the potential to be the most significant domestic policy change since the Patient Protection and Affordable Care Act known as ObamaCare was enacted in 2010.

Advocates, including President Biden, say the measure would cut child poverty almost in half. They also point out that it builds on bipartisan support for family formation. Senator Romney has a similar, even more financially generous, proposal. President Trump and congressional Republicans already doubled the child tax credit to $2,000 in 2017. Providing for a child’s basic needs makes the child more likely to grow up to become a productive adult, the argument goes.

Critics, including longtime welfare reformers, say that by making the payments unrelated to employment (unlike the earned-income tax credit) and unlinked to the presence of fathers, the payments will encourage young women to exit the paid workforce and incentivize single parenthood. By this read, the program is a sort of reincarnation of the old Aid to Families With Dependent Children, the “welfare” program President Clinton was elected in 1992 promising to end-as-we-know-it.

In a January 2020 column, I noted that American population growth had flattened under President Trump, as immigration slowed and demographics trended toward fewer births and more deaths. “The situation,” I concluded, “is an opportunity for a politician or an activist group seeking to restore the basic American idea that having more Americans — positive population growth — is good for the country.”

Good for President Biden for seizing the opportunity, I suppose, even if, as always, also, be careful what you wish for — you might get it.

The nature of the American Rescue Act — an emergency measure for Covid-19-relief — means that the program will be funded with borrowing, money-printing, inflation, and wishful thinking. If it is extended, Democrats will be tempted to pay for it by raising taxes.

That raises some fairness issues. Why should Americans without children have their money taxed away to pay for those who do have children? These childless Americans are already taxed to pay for public schools they don’t use and for health insurance and nutrition benefits targeted at poor children.

Any Democratic tax plan can be expected to punish high-earning, that is, economically productive, Americans by raising their taxes and giving the money to families with young children. The increased tax-credit phases out entirely at $170,000 in adjusted gross income for a married couple filing jointly.

Even a 2014 Republican plan proposed increasing the 25% income tax bracket to 35% to pay for an expanded child tax credit, so one can see where this is headed — toward tax-and-spend-and-redistribute.

America keeps pretty good vital record statistics, so an increase in live births owing to this increased child tax credit should be easy to track. Those skeptical of the idea that a mere $1,600 a year extra — barely enough to cover diapers or baby food — would affect as personal a decision as bringing a new baby into the world must not be familiar with the social-science literature.

Social conservatives will celebrate the decline in abortions. Liberals will celebrate the decline in child poverty. Pro-growth believers in human capital will celebrate the potential of these new children.

Skeptics of big government, though, will pause to acknowledge the concerns about the unintended consequences. And to ask how we ever got to a place where our most intimate decisions, such as conception and childbirth, became byproducts of congressionally crafted legislation.