Before I had even finished reading the first chapter of Diane Macunovich's new book, three things were crystal clear:

People matter: a society's demographics need to be considered explicitly when trying to understand or to forecast its economic behavior.

Einstein's conclusions about relativity apply to economies: changes in the relative size and age composition of a population can lead to major changes in its social and economic behavior.

Economic demographers rule! From now on, users of long-term forecasting models will need to include information on changes in age structure and cohort size if they wish to forecast events more than a few years ahead.