Strategic Asset Allocation

Academic finance has had a remarkable impact on many financial services. Yet long-term investors have received curiously little guidance from academic financial economists. Mean-variance analysis, developed almost fifty years ago, has provided a basic paradigm for portfolio choice. This approach usefully emphasizes the ability of diversification to reduce risk, but it ignores several critically important factors. Most notably, the analysis is static; it assumes that investors care only about risks to wealth one period ahead. However, many investors--both individuals and institutions such as charitable foundations or universities--seek to finance a stream of consumption over a long lifetime. In addition, mean-variance analysis treats financial wealth in isolation from income. Long-term investors typically receive a stream of income and use it, along with financial wealth, to support their consumption. At the theoretical level, it is well understood that the solution to a long-term portfolio choice problem can be very different from the solution to a short-term problem. Long-term investors care about intertemporal shocks to investment opportunities and labor income as well as shocks to wealth itself, and they may use financial assets to hedge their intertemporal risks. This should be important in practice because there is a great deal of empirical evidence that investment opportunities--both interest rates and risk premia on bonds and stocks--vary through time. Yet this insight has had little influence on investment practice because it is hard to solve for optimal portfolios in intertemporal models. This book seeks to develop the intertemporal approach into an empirical paradigm that can compete with the standard mean-variance analysis. The book shows that long-term inflation-indexed bonds are the riskless asset for long-term investors, it explains the conditions under which stocks are safer assets for long-term than for short-term investors, and it shows how labor income influences portfolio choice. These results shed new light on the rules of thumb used by financial planners. The book explains recent advances in both analytical and numerical methods, and shows how they can be used to understand the portfolio choice problems of long-term investors.

Auteur

John Y. Campbell received a BA from Oxford in 1979 and a PhD from Yale in 1984. He spent the next ten years teaching at Princeton, moving to Harvard in 1994 to become the first Otto Eckstein Professor of Applied Economics. Campbell has co-edited the American Economic Review and the Review of Economics and Statistics; he is a Fellow of the Econometric Society and the American Academy of Arts and Sciences, and a Research Associate and former Director of the Program in Asset Pricing at the National Bureau of Economic Research. His research concerns asset markets, the macroeconomy, and the links between them. Luis M. Viceira grew up in Santa Fe, Spain, and attended undergraduate college at the Universidad Autónoma in Madrid. In 1993 he came to the United States to attend graduate school, earning a PhD from Harvard in 1998. He has been a member of the Harvard Business School faculty since 1998, where he teaches Finance in the MBA program and in the Doctoral program. He is a Faculty Research Fellow of the National Bureau of Economic Research in Cambridge (MA, USA), a Research Affiliate of the Centre for Economic Policy Research in London (UK), and an associate editor of the Spanish Economic Review. His research concerns investments and asset prices. Viceira is also a member of the Academic Advisory Board of ABP Investments in The Netherlands.