portfolioafterlife
too fast for love
Given what we know from the research of such pioneers as Brinson et al., that the majority of the variation in returns between portfolios is explicable by the mix of underlying assets which they contain, basing return assumptions on the underlying asset returns seems like a sound approach to me.
Although it may seem counter-intuitive, reducing the exposure to ‘risky’ assets such as equities in favour of ‘less risky’ fixed interest investments can have the effect of increasing the risk of failure, even if it may reduce the portfolio’s volatility.
The volatility of a particular asset or asset class also fails to allow for the fact that a well constructed portfolio comprises multiple assets whose return patterns should be at least partially uncorrelated with each other. Holding two uncorrelated but volatile assets can result in a less volatile overall portfolio if the ups of one cancel out the downs of the other.
It is also worth remembering that since volatility is a measure of the variation in returns over time, it is prone to changing as those underlying returns change. Similarly, the correlations between assets are also not constant and as history reminds us frequently, they often increase in times of market stress. A further point is that large movements can occur more frequently than predictions suggest and but they are not evenly distributed between positive and negative; instead there are often more large negative movements than positive ones.

Why volatility isn’t the risk which should worry you - The Financial Bodyguard Blog Site
I recently read a consultation document regarding proposed changes to the way in which projections for money purchase pension schemes are calculated.
