I signed up at 62 for a number of reasons.
First, I had the option to take an early retirement package from a union job I had in my twenties. At 57, I contacted the union and they told me that I'd be waaayyyy smarter to wait until I was 62 because the benefit would be substantially higher. When I hit 62, I applied and was told that the fund was severely depleted and that I'd only get half what I would have gotten, had I taken the earlier number. Net result was five years of lost benefit and a 50% depreciation until I finally vapor lock...or the fund goes belly up...which ever occurs first.
When it came time for SS, I signed up the first nano second I turned 62.
Contributing data to the decision:
SS is an unfunded liability, not counted in the National Debt numbers or any other barometers of economic health. The demographic bubble of "Baby Boomers" is just about to hit prime time, which means that this will be the largest "entitlement" the planet has ever seen.
I look at the skyrocketing National Debt, the clinically brain dead GDP for the US, the recently approved budget that breaks all records for government spending, tanking markets in Japan and China who have their own demographic bubbles, the Baltic Dry Index, Container to Ship Indexes, absolutely surreal market fundamentals, Quantitative Easing un-ending, the massive bank/economic failures worldwide, the EU, austerity and the tidal wave of new welfare recipients we are expected to feed, clothe and house, and I arrive at a fairly straight forward personal strategy.
I don't exactly have the highest confidence that my money that went for all those years will be coming back in my direction. There is no one working to fund the 38.4 million Americans now arriving at the SS threshold, and no one on the Hill with the huevos to point to the fact that there is a tiny little problem looming beyond the bond and derivatives bubbles.
All of that said, it seemed prudent to un-retire and think seriously about providing an income stream that I am in direct control of. I'm working diligently on that and stocking up on dried food...
IMHO