For well over a century, actuaries have projected the financial experience of social security programs around the world. Policymakers – and actuaries themselves – have debated various aspects of these financial projections, such as: (a) the key economic and demographic assumptions, including mortality improvement and fertility trends, on which the projections are based, (b) the duration of the projections, which have ranged from just a few years to 75 or more years, and (c) the treatment of uncertainty by deterministic and stochastic methods. This paper focuses on this last aspect,
highlighting key issues related to the application of stochastic models, although the paper also touches on the first two aspects due to their interrelated nature.
