Hi Guys,
A major uncertainty when making a
retirement decision is the expected future market returns. A standard analytical tool that is frequently exercised when attacking this quagmire is Monte Carlo calculations.
When using a Monte Carlo approach, a constant issue is what to input as a likely returns profile as a function of the asset allocation and time. Many simulations deploy the historical statistical market segment data sets. Others use perturbed versions of these same data sets that reflect future expectations.
These inputs are the fundamental drivers that determine an allowable annual drawdown rate. Of course, the target goal is a high likelihood of portfolio survival for the specified
retirement period. That target goal is typically a 90 % to 95 % portfolio survival probability.
A recent paper addresses this essential, but cloudy, input issue of candidate future market rewards. Rather than using a random draw to initiate the overall process, this refined Monte Carlo approach starts with current bond returns and the present equity P/E ratio to guide the future returns profile.
This 17 page report by Blanchett, Finke, and Pfau is titled “Asset Valuations and Safe Portfolio Withdrawal Rates”. Here is the Link to the paper:
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2286146If you are not particularly inspired to examine the paper itself, here is a Link to a detailed opinion of that work:
http://www.kitces.com/blog/archives/480-Safe-Withdrawal-Rates-In-Todays-Low-Yield-Environment-Walking-On-The-Edge-Of-A-Cliff.htmlThis Nerd’s Eye View of the academic study fairly examines both the strong points and the shortcomings of the research work.
In its abstract, the research paper properly identifies the motivation for the study as follows: “Portfolio returns in the first decade of
retirement have an outsize impact on
retirement income strategies. Traditional Monte Carlo simulation approaches generally do not incorporate market valuations into their analysis.”
The referenced report employs a regression curve fitting approach to current bond yields as a point of departure for the fixed income modeling, and Robert Shiller’s cyclically adjusted price-to-earnings (CAPE) ratio model as an estimate of future equity market rewards. Inflation is incorporated into the formulation and is closely tied to the mid-term bond yield. As is usually the case, the overarching modeling is not completely accepted by market wizards without some controversy.
Historically, most earlier Monte Carlo studies endorsed a roughly 4 % annual drawdown rate to sort of guarantee a high portfolio survival likelihood. The referenced work challenges this assertion given today’s investment environment. That’s not unexpected since the input anticipated return schedules are muted relative to historical averages. The referenced study challenges the safety of the 4 % withdrawal chimera.
My takeaway from all these eloquent simulations is that any investor preparing for a
retirement should assemble a sufficiently robust portfolio such that its planned drawdown rate should be approximately 3 % less than the projected annual returns for the portfolio. For example, if your portfolio is designed to generate a 6.5 % annual return over the long haul, than a 3 % withdrawal schedule, adjusted for inflation, should deliver a comfortable 90 % to 95 % probability of success.
Also, an alert retiree will adjust that drawdown schedule if the portfolio suffers some shortfalls. Monitoring and flexibility are always vital elements in any planning and execution exercise.
All this need not be complex rocket science. As Albert Einstein said: “ Out of clutter, find simplicity. From discord, find harmony. In the middle of difficulty, lies opportunity.”
Monte Carlo tools provide such an opportunity. I really like Monte Carlo simulations, but I also recognize their limitations. They serve best in providing guidelines. Here is a Link to a very simple and useful Monte Carlo tool that is easily used:
http://www.moneychimp.com/articles/volatility/montecarlo.htmThe code provides an estimate of portfolio survival probability. The ease of input and speed of execution allows the user to do many probing parametric cases quickly. Enjoy.
Monte Carlo analysis is applied only when definitive, precise assessments can not be made. That’s exactly a characteristic of the marketplace. That’s particularly true when planning for
retirement, and forced to project highly uncertain market returns. I do recommend you use available Monte Carlo analysis when doing your
retirement planning. Many websites offer that service.
Good luck to all you folks who are now evaluating the
retirement option. Given the results of the referenced study, that luck is most productive to your survival prospects when gifted early in the
retirement years.
Best Regards.