Paper recommends flexible withdrawals   The two traditional
strategies rely on withdrawing a fixed percentage of a portfolio
each year. Vanguard’s analysis found long-term problems with
each method.  The paper first looked at the so-called 4 percent
rule. A retiree using this strategy would withdraw that
percentage of the amount in their retirement funds at the
beginning of each year. Because a portfolio’s assets would rise
and fall with the markets, this strategy makes it difficult to
plan spending. The upside to this method is that assets would
never be depleted.  The paper also looked at a method that uses
the 4 percent rule, but adjusts the amount each year by the
inflation rate. This strategy ensures retirees have a stable
amount to spend each year, but is unresponsive to market ups and
downs. The chances the fund will last 35 years are 78 percent,
the lowest of the three methods, including the “dynamic” one
that follows.  Finally, Vanguard analyzed a modified version of
the two methods. This “dynamic” m