Possibly longer than most people are planning for:
The IMF asks what would happen if life expectancy by 2050 turns out to be three years longer than current projected in government and private retirement plans: "[I]f individuals live three years longer than expected–in line with underestimations in the past–the already large costs of aging could increase by another 50 percent, representing an additional cost of 50 percent of 2010 GDP in advanced economies and 25 percent of 2010 GDP in emerging economies.
The Dish 