Absolute Momentum, Sustainable Withdrawal Rates and Glidepath Investing in US Retirement Portfolios From 1925

Abstract

A significant part of the development in pension provision in many countries is the emergence of ‘Target Date Funds’ or TDFs. In this paper we examine the proposition of de-risking through life and the guidance offered by TDFs in the decumulation phase following retirement. We investigate the withdrawal experience associated with Glidepath Investing in the US since 1925 for conventional bond-equity portfolios. We find one very powerful conclusion: 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, i.e. the bad luck of a poor sequence of returns early in decumulation. We show that diversifying assets over time by switching between an asset and cash in a systematic way is potentially more important for the retirement income experience than diversifying one’s portfolio across asset classes. We also show that Glidepath investing is only sensible 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.

Keywords: Sequence Risk, Perfect Withdrawal Rate, Decumulation, Absolute Momentum, Trend Following

JEL Classification: G10, G11, G22