This is my party, so I can tickle my bias if I want to.
We confirm what others have already demonstrated, but we extract markedly more statistical significance by adapting a polynomial curve-fitting technique pioneered by Fair and Dominguez (1991), to this new purpose. In our work, we find that a growing roster of young adults (age 15-49) is very good for GDP growth, a growing roster of older workers is a little bad for GDP growth, and a growing roster of young children or senior citizens is very bad for GDP growth.
Ok, here are some population pyramids:
According to the 1990 population pyramid, we should have been experiencing a boom in the 90s.
This boom should have abated in the 2000s.
By 2025, the transition is almost complete and the economy reaches a demographic steady state.
I haven’t read the paper, but I know what Scott Sumner has taught me: falls in nominal GDP are super duper bad. And demographics appear to have contributed to this.
AND, that contribution is ending.