Designing Target-Date Funds with a Declining CVaR Glidepath
Summary
This framework links a target-date fund’s investment objective to pension design inputs, such as contribution rates, working years, retirement age, and replacement-rate goals. Instead of prescribing age-based asset limits alone, a sponsor specifies a declining portfolio-level Conditional Value-at-Risk constraint intended to leave managers room to pursue the required return while controlling risk.
The evaluation does not assume managers choose an optimal portfolio each month. It samples allocations that meet the CVaR constraint and assesses the average probability of reaching the target, alongside cumulative risk over the fund’s life. Applied as a proof of concept to Chile’s pension reform, the analysis uses nine Chilean and global asset classes over a 40-year accumulation horizon. It identifies the age when risk begins declining as a consequential design choice and finds that low contribution density can limit the ability to meet the objective. Results depend on the modeled setting and do not establish that sampled allocations represent actual manager behavior.
Key ideas
- A target return can be derived from pension design goals and participant circumstances.
- A declining CVaR constraint gives a sponsor a direct way to shape portfolio risk over time.
- Evaluating admissible allocations avoids assuming managers select the best portfolio each period.
- The framework tracks both target-return success probability and cumulative risk.
- Contribution density can constrain outcomes beyond what portfolio design can remedy.
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Full text
# A Declining CVaR Glidepath Framework for Target-Date Fund Design with an Application to the Chilean Pension System # A Declining CVaR Glidepath Framework for Target-Date Fund Design with an Application to the Chilean Pension System 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.
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