Explain two different weaknesses of using each of the
benchmarks to measure the performance of the portfolio.
• A market index may exhibit survivorship bias; firms that have
gone out of business are removed from the index resulting in a
performance measure that overstates the actual performance had
the failed firms been included.
• A market index may exhibit double counting that arises because
of companies owning other companies and both being represented
in the index.
• It is often difficult to exactly and continually replicate the
holdings in the market index without incurring substantial trading
costs.
• The chosen index may not be an appropriate proxy for the
management style of the managers.
• The chosen index may not represent the entire universe of
securities (e.g., S&P 500 Index represents 65–70 percent of U.S.
equity market capitalization).
• The chosen index may have a large capitalization bias (e.g., S&P
500 has a large capitalization bias).
• The chosen index may not be investable. There may be securities
in the index that cannot be held in the portfolio.
• This is the most difficult performance measurement method to
develop and calculate.
• The normal portfolio must be continually updated, requiring
substantial resources.
• Consultants and clients are concerned that managers who are
involved in developing and calculating their benchmark portfolio
may produce an easily-beaten normal portfolio making their
performance appear better than it actually is.
able to invest in the median manager portfolio.