Recently I noticed that the age for joining AARP is 50. Wasn't it 55 not long ago?

I also noticed on some job applications recently that age discrimination disclaimers now read 40 & over whereas before I don't recall explicit ages listed but I think the implied ages were 50-55. Does anyone know how they came up with age 40?

In the first situation it is probably the AARP wanting to increase it's base. In the second it is probably just evidence of a tight job market.

Anyway, I thought life expectancies and productivity at older ages were increasing. I guess this is just more evidence of a major demand problem.