Policy Simulation Group

Pension Projection Models

History of the PSG Models

SSASIM has been under continuous development since 1994, when it started as part of the work of the Social Security Advisory Council. Development was sponsored by EBRI for several years during the late 1990s. Since 2000, the development of SSASIM has been sponsored by the Policy Simulation Group and by users of the PSG models, with major enhancements supported by SSA/ORDP.

PENSIM has been under continuous development since 1997, when DOL/EBSA awarded the initial development contract. A no-pension version of PENSIM has provided life histories for GEMINI social security simulation since 2001. Beginning in early 2007, the publicly distributed version of PENSIM has been able to simulate employer-sponsored pensions.

GEMINI was initially developed in 2001 by the Policy Simulation Group to create a social security microsimulation capability by combining the life history simulation capabilities of PENSIM and the social security tax and benefit simulation capabilities of SSASIM. Then beginning in 2004, SSASIM was enhanced to use this microsimulation capability to produce solvency estimates for the social security trust funds.

Version History

• detailed description of enhancements introduced in current version of the PSG models
• summary of enhancements introduced in earlier versions since 2004