Post Script to Faster and Easier SWR Calculations

I have written this because I received a remark about the improvement. This is only an artifact. There is no actual improvement.

I have successfully taken advantage of linearity to speed up withdrawal rate calculations. It is a dramatic improvement. I posted the details in Faster and Easier SWR Calculations.

However, my original approach remains the most accurate. A person can draw his most accurate inferences from data that come closest to what he is after. For example, if you are interested in Historical Surviving Withdrawal Rates, you get the most accurate information by taking a complete set of HSWR data. If you are interested in Half Failure Safe Withdrawal Rates, you get the most accurate information by taking a set of Half Failure Rate data.

Comparing the HSWR50/HDBR50 results from Calculated Rates of the Last Decade with an earnings yield 100E10/P of 3.5% with Faster and Easier SWR Calculations, the newer approach is more optimistic. Its Safe, Calculated and High Risk Withdrawal Rates are 3.72%, 4.53% and 5.16%. The older, more accurate method calculates these rates as 3.03%, 4.04% and 5.05%.

The withdrawal rates in my example were 3.0%, 4.0%, 5.0% and 6.0% in Faster and Easier SWR Calculations. The most accurate answers from such data should be most accurate when they fall into the middle range of 4.0% to 5.0%.

Have fun.

John Walter Russell
I posted this on May 9, 2005.