Population decline is a really serious ailment. It makes for an eternally shrinking economy and a death-spiral, as the value and prosperity of the place decays

Population decline is a really serious ailment. It makes for an eternally shrinking economy and a death-spiral, as the value and prosperity of the place decays YoY. Less people means less demand, means less businesses, less jobs, less tax revenue, etc. It is reversible, by changing expectations of the future, to prevent people from leaving and to attract new people, but a few years of shrinking population would make the spiral very hard to revert.