Measuring the Significance of Diversification Gains

This article investigates whether investing in alternative investment media provides statistically significant increases in portfolio performance. Employing methodology introduced by Kandel and Stambaugh (1987) and Gibbons, Ross and Shanken (1989), we measure the statistical significance of diversification gains for portfolios containing real and financial domestic assets, as well as international debt and equity issues. The NCREIF real estate series is further examined using the Geltner (1993) adjustment to the risk measure. In the 1978B93 sample period, neither international assets nor unadjusted real estate ever result in statistically significant increases in portfolio performance. When the Geltner adjustment is made, the allocation to real estate is substantially reduced in the expanded portfolio and also fails to result in a statistically significant increase in portfolio performance. These results may help to resolve the paradox between current portfolio allocations to real estate in practice and those suggested in the literature.

On Teaching Multi-Criteria Decision Making with a Robot Assistant

We propose a system and method for a robot assistant for teaching multi-attribute decision making (MCDM). Through questions and answers in natural language, the robot assistant learns the user’s preferences on multiple criteria involving a selection decision and makes recommendations using data on each criterion and the learned user preferences. It will include a use-case demonstration where NAO the robot will assist a human in forming a simple portfolio of mutual funds. Presenters will illustrate the architecture of the robot assisted MCDM and describe a method that is extensively used to structure complex decision problems and has been applied to a variety of problems in a diverse set of disciplines, such as selecting a project, selecting a life insurance contract, selecting public relations firms, deciding on library acquisitions, hostage negotiations, selecting sites for wildlife management, and selecting a nonprofit for donation

Modeling Market Reactions to Auditor Changes Using Variable Selection Algorithms: A Meta-Analysis

Market reactions to auditor change filings have been studied over a long period in the literature. We provide a review of the literature on market response to auditor changes and identify a superset of variables used in published research. Applying methods from machine learning to optimize variable selection, we build models that explain market reaction to auditor changes. We compare the performance of our models with the performance of the models that use subsets of variables examined in a select list of studies in the literature. Our meta-analysis results in an improvement in model fit compared to the analysis used in prior studies

ESG Investing: A Decision-Making Paradox?

Debates about the attributes of environmental, social, and governance (ESG) investing are ongoing. The definitions, integration methods, performance outcomes, and data consistency are all developing. Against this backdrop, we explore whether ESG investing constitutes a decision-making paradox in which selecting a desirable set of stocks for inclusion in an ESG portfolio simultaneously requires adopting a desirable decision-making method to select those stocks. Comparing the results from two multi-criteria decision-making methods for selecting ESG portfolio stocks, we illustrate the sensitivity of the resulting selections to various approaches. We recommend a series of practical steps for resolving the paradox

Diversification in Portfolios of Individual Stocks: 100 Stocks Are Not Enough

We examine returns and ending wealth in portfolios selected from 1,000 large U.S. stocks over a 20-year holding period. Shortfall risk, the possibility of ending wealth being below a target, is a useful metric for long horizon investors and is consistent with the Safety First criterion. Density functions obtained from simulations illustrate that shortfall risk reduction continues as portfolio size is increased, even above 100 stocks. A slightly lower risk can be achieved in small portfolios by diversifying across industries, but a greater reduction is obtained by simply increasing the number of stocks. Copyright 2007, The Eastern Finance Association.