One of the things to consider in light of the city health department’s latest report on births, deaths, and other vital statistics is what life would have been like in New York — and America, for that matter — without, say, Frank Sinatra, Ray Charles, Truman Capote, or, to pick another name, Oprah Winfrey. We mention those names because they are individuals who were born to teenage mothers. Buried in the health department’s report is news that the city has been seeing a plunge in its birth rate, which has dropped 8% in the past decade to its lowest point in 25 years. This is led by what the health department calls a “dramatic” drop in the rate of births to women below the age of 20.

This is news for New Yorkers to think about. The health department is boasting about a surge in life expectancy, which is certainly good news. Life expectancy of New Yorkers, the city reckons, has increased, in the past year alone, by nearly five months. The department quotes the health and mental hygiene commissioner, Dr. Thomas Frieden, as saying, “New Yorkers are living longer than ever,” adding that “an additional 300,000 New Yorkers now have a regular doctor and are increasingly getting the screenings they need.”

But all this comes as the United States Census is about to report that New York State is one of but four states experiencing a net loss of population; the details are on our page one. The census bureau estimates that 255,766 more people moved out of New York to other states than into the state between 2005 and 2006. New York State is in the sorry company of hurricane-ravaged Louisiana and Michigan, home of the collapsing domestic auto industry, as population losers. If trends continue, New York State will lose two congressional seats in the next decennial census, and we will slip behind Florida to become the fourth most populous state in the union rather than the third.

The health department’s report on the birth rate this week sketches a quiet catastrophe in the city — the fact that its birth rate has plunged to a 25-year low. In the past year, the birth rate stood at only 15.1 children for every 1,000 New Yorkers. It dropped, according to the health department, an astonishing 8% in the past decade alone. Our birth rate is better, according to a chart from the World Fact Book on the Wikipedia Web site, than such faltering giants as, say, France (11.99 births per 1,000) or Germany (8.25) or Japan (9.37). But it is dwarfed by, say, Niger (50.73) or even war-torn Iraq (31.98), not to mention population growth worldwide of 20.05 births per 1,000 persons.

The plunging is part of a national trend, the health department reports. New York itself has a slightly better birth rate than America as a whole. But that’s cold comfort. As is the fact that the health department attributes the decline of the birth rate in the past decade “almost entirely”to a “fall in the number of teen births.”

There seems to be a view that teenage births are somehow a bad thing. But it seems to us that it’s not the births that are the problem. It’s the environment that marginalizes teen motherhood, encourages our youth to delay marriage, provides too few incentives for family-building, and too few jobs for the fathers and mothers. What is needed is not scolding from the government but lower taxes, fewer regulations, and overall pro-growth policies.

We’re not saying there’s anything wrong with having a mother who was over 20. It’s perfectly respectable. Commissioner Frieden’s office refuses to say how old his mother was when he was born, but Mayor Bloomberg’s mother was 33 when he was born, Thomas Jefferson’s was 23, and Teddy Roosevelt’s 24, to name but a few magnificent mothers. But lots of other magnificent mothers were under 20. Billie Holliday’s was 13, Eric Clapton’s 16, Lance Armstrong’s 17, LeBron James’s 16. We’re happy to have women and men decide for themselves when to have children. But when a trend develops like the drop in the birth rate in New York, it’s a sign that we need public policies designed to encourage more people and make New York a hospitable place for all people who want to have children.