Portfolio Optimization and Long-Term Dependence
Carlos León () and
Alejandro Reveiz ()
BORRADORES DE ECONOMIA from BANCO DE LA REPÚBLICA
Abstract Whilst emphasis has been given to short-term dependence of financial returns, long-term dependence remains overlooked. Despite financial literature provides evidence of long-term´s memory existence, serial-independence assumption prevails. This document´s long-term dependence assessment relies on rescaled range analysis (R/S), a popular and robust methodology designed for Geophysics but extensively used in financial literature. Results correspond to most of the previous evidence of significant long-term dependence, particularly for small and illiquid markets, where persistence is its most common kind. Persistence conveys that the range of possible future values of the variable will be wider than the range of purely random and independent variables.Ahead of R/S financial literature, authors estimate an adjusted Hurst exponent in order to properly estimate the covariance matrix at higher investment horizons, avoiding the traditional -independence reliant- square-root-of-time rule. Ignoring long-term dependence within the mean-variance portfolio optimization results in concealed risk taking; conversely, by adjusting for long-term dependence the weight of high (low) persistence risk factors decreases (increases) as the investment horizon widens. This alleviates some well-known shortcomings of conventional portfolio optimization for long-term investors (e.g. central banks, pension funds and sovereign wealth managers), such as excessive risk taking in long-term portfolios, extreme weights, home bias, and reluctance to hold foreign currency-denominated assets.
Keywords: Portfolio optimization; Hurst exponent; long-term dependence; biased random walk; rescaled range analysis. (search for similar items in EconPapers)
JEL-codes: C14 G11 G20 G32 (search for similar items in EconPapers)
References: Add references at CitEc
Citations: Track citations by RSS feed
Downloads: (external link)
Our link check indicates that this URL is bad, the error code is: 403 Forbidden (http://www.banrep.gov.co/docum/ftp/borra622.pdf [301 Moved Permanently]--> https://www.banrep.gov.co/docum/ftp/borra622.pdf)
Chapter: Portfolio optimization and long-term dependence (2011)
Working Paper: Portfolio Optimization and Long-Term Dependence (2010)
This item may be available elsewhere in EconPapers: Search for items with the same title.
Export reference: BibTeX
RIS (EndNote, ProCite, RefMan)
Persistent link: https://EconPapers.repec.org/RePEc:col:000094:007487
Access Statistics for this paper
More papers in BORRADORES DE ECONOMIA from BANCO DE LA REPÚBLICA
Bibliographic data for series maintained by Clorith Angélica Bahos Olivera ().