Some South Dakota population trends are increasing while others are decreasing.

That’s according to state demographer and South Dakota State University Professor Weiwei Zhang, who testified before the South Dakota Legislature’s House State Affairs Committee this morning (Jan. 10, 2024).

On the one hand, some South Dakota counties have seen considerable growth, including Minnehaha, Lincoln, and Meade Counties. Sioux Falls and Rapid City are growing, with Sioux Falls outpacing Rapid City’s growth.

On the other hand, the state birth rate is down, the fertility rate is down, and the mortality rate is up.

Zhang says South Dakota is at its population replacement of 2.1 children per family, higher than the national rate of 1.7 to 1.8 children per family. At that rate, Zhang says the U.S. could see a population decline, not considering immigration. She says some European and Asian countries have even lower rates of replacement. Even with the declining birthrate, she says South and North Dakota lead the nation in fertility rate.

The state’s life expectancy rate, Zhang said, has decreased by about one year to 76.7 from 78.9. Similarly, she said this is true of all states seeing a decrease in life expectancy due to the COVID-19 pandemic.

As to in-migration within the U.S., most new South Dakota residents have come from Minnesota, Iowa, California, Nebraska, and North Dakota over the past decade. About 3.5% of the population are “state-to-state movers.” Similarly, about 3.5% of the South Dakota population is foreign-born, with most new residents coming from Asia and Africa and fewer coming from Europe than in past South Dakota history. 

Zhang also expects a decrease in school-aged children after a decade or so of rising K-12 enrollments.

Story by Todd Epp, South Dakota Broadcasters Association.