Exploring Long Island fertility rate trends

Long Island’s fertility rate has been trending upwards since 2016, with an average of 51 births per 1,000 women in 2019.

But another way to look at this is by calculating the total fertility rate (TFR), which averages the number of children a woman would have if she survives all her reproductive/childbearing years.

The TFR is an average and can’t predict how many children a woman will have – different women make their life decisions based on varying factors.

Before we look at what Long Island’s TFR is, we should know that the “magic number” for TFR is 2.1, also known as “replacement level fertility.” This is the estimated rate required for one generation to replace itself without migration.

In other words, assuming absolutely no inflow/outflow migration on Long Island, we would need a TFR of 2.1 to maintain the population level.

So what does Long Island’s TFR look like, and how does it compare with the state and nation? Using Census data, we can get a general idea (keep in mind however Census data might differ from estimates by the CDC and others).

Long Island’s TFR has been trending upwards in the recent years, but is still short of the 2.1 threshold.

At these rates, what it shows is that without incoming migration, neither the U.S., New York or Long Island would be able to grow its population based solely on births.

However, while 2.1 is the generally accepted threshold, factors such as mortality rates can affect the actual replacement level fertility rate for each region.