The Rehabilitation of Glidepath Investing

In this paper we examine the proposition of de-risking through life and the guidance offered by TDFs in the decumulation phase following retirement. Using both Monte Carlo methods along with actual historical experience we investigate the withdrawal experience associated with Glidepath Investing in the US since 1925 for conventional bond-equity portfolios. We find two very powerful and practical conclusions. First, that smoothing the returns on individual assets by simple absolute momentum or trend following techniques is a potent tool to enhance withdrawal rates, often by as much as 50% per annum. And, perhaps of even greater social relevance is that it removes the ‘left-tail’ of unfortunate withdrawal rate experiences, that is, the bad luck of a poor sequence of returns early in decumulation. We show that diversifying assets over time by switching between a risky asset and cash in a systematic way is potentially more important for the retirement income experience than diversifying one’s portfolio across a range of risky asset classes. In particular the willingness to tactically de-risk and re-risk allows the investor to stay exposed to equities in selective calendar fashion for far longer with reduced potential for painful drawdowns and raised potential for higher withdrawal rates. Second, and very importantly, we also show that Glidepath Investing is indeed a very sensible strategy within a few years of the target date. This finding provides succour to enthusiasts for target date investing in the face of the growing hostility in the literature