Automatic Adjustment Mechanisms (AAMs) are legal instruments that help social security systems respond to demographic and economic changes. In Brazil, the Social Security Factor (SSF) was introduced in the late 1990s as an AAM to link retirement benefits to life expectancy at the retirement age, hoping to promote contributory justice and discourage early retirement. Recent research has highlighted the limitations of right-censored life tables, such as those used in Brazil. It has recommended using the gamma-Gompertz-Makeham (\(\Gamma GM\)) model to estimate adult and old-age mortality. This study investigated the impact of right-censoring on the SSF by comparing the official SSF and other social security metrics with a counterfactual scenario computed based on fitted \(\Gamma GM\) models. The results indicate that from 2004 to 2012, official life tables may have negatively impacted retirees’ income, particularly for those who delayed their retirement. Furthermore, the \(\Gamma GM\) fitted models’ life expectancies had more stable paths over time, which could have helped with long-term planning. Our findings are significant for policymakers as they highlight the importance of using appropriate mortality metrics in AAMs to ensure accurate retirement benefit payments. They also underscore the need to consider the potential impacts of seemingly innocuous hypotheses on public action outcomes. Overall, this study provides valuable insights for policymakers looking to enhance the effectiveness and fairness of social security systems.

自动调整机制（AAM）是帮助社会保障体系应对人口和经济变化的法律工具。在巴西，社会保障系数（SSF）于 20 世纪 90 年代末作为 AAM 引入，将退休福利与退休年龄的预期寿命联系起来，希望促进缴费正义并阻止提前退休。最近的研究强调了右删失生命表的局限性，例如巴西使用的生命表。它建议使用 gamma-Gompertz-Makeham (\(\Gamma GM\)) 模型来估计成人和老年死亡率。本研究通过将官方 SSF 和其他社会保障指标与基于拟合 Gamma GM 模型计算的反事实场景进行比较，调查了右审查对 SSF 的影响。结果表明，从 2004 年到 2012 年，官方生命表可能对退休人员的收入产生了负面影响，特别是对于那些延迟退休的人。此外，\(\Gamma GM\) 拟合模型的预期寿命随着时间的推移具有更稳定的路径，这可能有助于长期规划。我们的研究结果对于政策制定者来说意义重大，因为它们强调了在 AAM 中使用适当的死亡率指标以确保准确的退休金支付的重要性。他们还强调需要考虑看似无害的假设对公共行动结果的潜在影响。总体而言，这项研究为寻求提高社会保障体系有效性和公平性的政策制定者提供了宝贵的见解。