the labor force participation rate.
For the past 40 years or so we could rely upon more and more women to enter the labor force and largely keep upward pressue on GDP growth which would minimalize if not mute the effect of recessions.
But women are participating at rates equal to men now, and now that Gen X women are coming of child birthing age, they are starting to drop out of the labor force bringing the trend back downwards. This combined with the discouraging effects of the housing crash, is resulting in an overall decrease in the labor force participation rate, meaning less and less people are looking for work when in order to afford the retiring masses we need more people than ever working in the economy.
Again, you wonder why the dollar is tanking.