Maybe you think you don’t care that Americans are having babies later in life and, therefore, fewer overall.

Let’s put it this way: Who’s going to be contributing the Social Security taxes down the road that will be paid out to you in retirement? Or anyone as lifespans lengthen but the workforce shrinks?

Now that we have your attention, here’s the problem: For a variety of perfectly understandable reasons, women in the developed world are choosing to have children later in life.

This naturally means fewer wee ones overall during the course of a woman’s child-bearing years. Which is fine for that individual family. But collectively that means an ultimate national shortage in workers earning wages and paying taxes to support the bubble of adults aging into retirement years.

It’s gotten so serious in some places that Hungary, for instance, has relieved women of paying any income taxes for the rest of their lives if they have four children.

The saving grace for the United States long-term is that millions of people want to become immigrants here.

President Trump’s proposed immigration package involves changing the country’s immigration criteria to be more selective and less happenstance. Still taking a dollop of refugees but moving away from a lottery, family connection and refugee status to admitting more newcomers based on merit, as many countries like Canada currently do.

You bring skills or a higher education you get XX points. You bring savings that virtually guarantee you will not require government assistance, you get XX points. You bring a skill on a list of desired ones, XX points. You speak English already, you get X points.

Decades ago my grandfather was Canada’s immigration officer in Scotland. Every month he would get a government recruiting quota from Ottawa — two carpenters, three electricians, two teachers, one shipyard worker, etc. He was to find such workers, check their backgrounds and sign them and their families up to move to Canada.

It makes perfect sense for a country rationally constructing a modern society that doesn’t have “Send me your huddled masses” as a de facto immigration motto on a statue.

The Centers for Disease Control recently reported the U.S. birth rate last year was the lowest it’s been in three decades, especially for younger women.

The latest overall female fertility rate for a woman was 1.7 babies in her lifetime. That’s down two percent again in the last two years and well below the 2.1 rate statistically needed for each generation to maintain a society’s population.

The reasons behind this developments are many and logical: marrying later in life, greater access to birth control that’s helped reduce teen pregnancies, a more educated society, especially among women who’ve received greater empowerment over their lives, including improved career choices.

The CDC found one other ray of hope: While the birth rate continued to decline for younger women, it rise slightly for women in their late thirties and early forties.

OK, now you know what your national duty is.