When the Social Security Act was first put into place, average life expectancy was less than 65 years. As of 2009 in this country life expectancy at birth (male and female combined, and all races) was a little over 78 years.
In other words, when the SS Act was passed, it was expected that only half of the birth population would receive any benefits.
I mention life expectancy at birth because that number gets higher as you live longer. As of 2009 in this country life expectancy for people who were age 65 that year (male and female combined, and all races) was a little over 83.6 years.
I read somewhere that roughly 65% of all government-paid medical expenses were incurred to keep people alive during their last year of life. I haven’t researched that to see if it is true or not, but it’s probably not far off.
Below is a chart of US (Federal Level) government spending versus GDP. Everything with a color accounts for Medicaid, Medicare, SS, and interest. Notice that in 2010, those colors account for over half of government revenue. Interest will accelerate as interest rates increase (inevitable compared to now) and as the deficit increases (history shows as inevitable under current governments worldwide).
All business entities are stable if their mature growth rate stabilizes within a relatively narrow window parallel (if not around) Real GDP (the word Real meaning that inflation is accounted for). The definition of a bubble is when those things grow faster than GDP.
Rule Number 1: all bubbles pop.
My opinion is that a Democracy (either a Pure Democracy, or a Representative Democracy such as ours wherein everyone has a vote and there are no term limits) will eventually pop. Greed and laziness eventually wins. There is no form of government yet devised that wont eventually pop. That means that there is at least Hope. People are like neutrons -- there is a point whereat there are too many of them too close together, referred to as critical mass. The result is an explosion and total destruction. After the smoke clears, life starts over.