And with an aging population and smaller working age people it will only get worse.
In the United States specifically, it is expected that the Social Security trust fund will run out by 2034. At that point, there will only be enough revenue coming in to pay out approximately 77% of benefits.
The Pension Time Bomb, $400 Trillion by 2050.
Link: http://www.visualcapitalist.com/pension-time-bomb-400-trillion-2050/