"This under-18 measurement is highly problematic – a recent USA Today analysis of the 2010 census found that 95% of U.S. counties lost population in the under-18 demographic. Overall, the under-18 population remained relatively static despite an overall 9.7% growth in total U.S. population. Households with children dropped from 36% in 2000 to 33.5% in 2010. To find the areas that have gained population in the under-18 group, "all you have to do is look for Latino immigrants. They are the only group in the U.S. that is producing children above replacement rates" said Kevin Stolarick, Research Director for the Martin Prosperity Institute in Toronto.
Yes, population loss is a metric that needs to be tracked and measured - but it should not be equated with death. If that were simply the case, Chicago would be a dying city, since it lost nearly 7% of its population from 2000 to 2010. As human beings we stop "growing" in our early 20s, yet we hardly think of a 25-year-old as dying - still, at a cellular level, they are dying in the same way that these cities are dying."
He argues that losing population is not the same as losing, hope, purpose, or the livelihood of cities.