**6. Conclusions**

Typical default strategies available to DC plan members include target date funds (i.e., glide path) and balanced funds (constant proportion). Both of these strategies have high probabilities of shortfall and large standard deviations of real terminal wealth.

We define an acceptable probability of success as a 90% probability of achieving 80% of the real desired terminal wealth goal. QS optimal strategies reduce the probability of shortfall significantly, compared to the ubiquitous glide path and balanced portfolio strategies, but not to within an acceptable range.

Assuming an optimal QS strategy, acceptable probabilities of shortfall can be obtained by


Our main conclusion is that current practices in DC plans with typical target benefits and default investment strategies have unacceptably high probabilities of shortfall. This has major ramifications for the many organizations which are shifting to DC plans.

Our results are based on the past 90 years of US market data. It is possible to argue that future market returns will be lower than observed in the past. The implication of such an assumption is that the probability of success for a DC investor would be even lower than we have reported here. In this case, the situation for DC plan investors would be even more dire than we suggest.

**Author Contributions:** All authors contributed equally in all aspects to this paper.

**Funding:** P. A. Forsyth's work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) gran<sup>t</sup> RGPIN-2017-03760.

**Conflicts of Interest:** The authors have no conflicts of interest to report.
