*The data and analysis from this post are part of an ongoing population projection being down with colleagues at UND.
Among all the concerns related to North Dakota the population has long been at the top of the list. This is as it should be since population is a significant constraint on economic activity. There are two possibilities for the source of the issue: fertility or migration. Why do I leave out mortality?
There is no evidence that mortality experience in North Dakota is largely different from the US experience (I am acknowledging that I am not addressing that there are subpopulations in the state for which there are enormous differences such as Native American males). The fact is that significant deviations from the mortality experience from other places would be noted and addressed in all likelihood, likely though a process such as migration.
For this post I look at fertility and the data demonstrate remarkable stability in fertility rates for the state of North Dakota as a whole. Over the course of 15 years there is not a significant deviation in fertility rates for any of the major age cohorts. While there is some evidence of a potential delaying of fertility (a decline in the rate for 25-29 and an increase in 30-34) there is not a strong evidence of switching nor is there significant variation from year to year.
One of the significant conclusions one can draw from this is that increases in births in North Dakota are not due to significant behavioral changes among the age cohorts. It is more likely the case or consequence of population change among females of childbearing years. An interesting policy implication of this is that the retention of children born to these age cohorts is an important means of keeping population increased at this time and over time.
To provide further insight we need an examination of the distribution of births and fertility within the state. This can reveal whether fertility changes are associated with a specific economic activity either directly or indirectly.