A Declining CVaR Glidepath Framework for Target-Date Fund Design with an Application to the Chilean Pension System
一个递减CVaR下滑路径框架用于目标日期基金设计及其在智利养老金系统中的应用
Israel Muñoz, Fernando Suárez, Omar Larré, Arturo Cifuentes
AI总结 提出一个通过递减条件风险价值约束控制风险的目标日期基金设计框架,以智利2025年养老金改革为例,发现过渡年龄是关键设计参数,缴费密度是硬约束。
详情
- Comments
- 29 pages, 3 figures
我们提出了一个框架,用于围绕明确的回报目标设计目标日期基金(TDF),同时通过递减的条件风险价值(CVaR)约束直接在投资组合层面控制风险。在这种方法中,监管机构或发起人指定一个CVaR下滑路径,使投资组合经理有足够的灵活性以相当高的概率达到目标回报。目标回报由养老金设计输入(如退休年龄、缴费率、工作年限、预期寿命和替代率目标)外生决定。这与传统的TDF设计不同,后者设定年龄依赖的资产类别限制,而没有与所需回报明确关联。该方法的一个关键特征是它不假设经理在每个时期选择最优投资组合。相反,经理每月从满足CVaR约束的投资组合集合中抽取一个配置。这产生了对每个下滑路径的保守评估:成功概率是允许配置的平均值,而非最佳情况结果。我们引入了两个性能指标:达到目标回报的概率和TDF生命周期内累积的风险。作为概念验证,我们使用九种智利和全球资产类别以及40年的积累期,将该框架应用于智利2025年养老金改革。结果表明,风险开始下降的过渡年龄是最重要的设计参数,并且缴费密度充当硬约束:低于临界阈值时,仅靠投资组合设计无法补偿结构性低缴费。该框架是通用的,可以应用于任何围绕明确回报目标设计的TDF。
We propose a framework for designing Target-Date Funds (TDFs) around an explicit return objective while controlling risk directly at the portfolio level through a declining Conditional Value-at-Risk (CVaR) constraint. In this approach, the regulator or sponsor specifies a CVaR glidepath that gives the portfolio manager enough flexibility to reach a target return with a reasonably high probability. The target return is determined exogenously from pension-design inputs such as retirement age, contribution rate, working years, life expectancy, and replacement-rate goals. This differs from conventional TDF design, where age-dependent asset-class limits are set without an explicit link to a required return. A key feature of the method is that it does not assume the manager selects an optimal portfolio each period. Instead, each month the manager draws an allocation from the set of portfolios satisfying the CVaR constraint. This yields a conservative evaluation of each glidepath: success probabilities are averages over admissible allocations, rather than best-case outcomes. We introduce two figures of merit: the probability of meeting the target return and the cumulative risk assumed over the life of the TDF. As a proof of concept, we apply the framework to Chile's 2025 pension reform using nine Chilean and global asset classes and a 40-year accumulation horizon. The results show that the transition age at which risk starts to decline is the most consequential design parameter, and that contribution density acts as a hard constraint: below a critical threshold, portfolio design alone cannot compensate for structurally low contributions. The framework is general and can be applied to any TDF designed around an explicit return objective.