Constraints on Asset Allocation
Real World Issues Real-world events often cause deviations from the optimal asset allocation... Read More
The choice of benchmark often has a significant effect on the assessment of manager performance. Investment managers should be compared only with benchmarks that reflect the universe of securities available to them. A valid benchmark must satisfy certain criteria. The following are characteristics of a valid benchmark by using the definitive list from Bailey and Tierney (1998). (Together they spell SAMURAI)
Once a benchmark is constructed, its quality can be tested using the following formula, which will be built up piece by piece for understanding.
First, state the identity where a portfolio's return (P) is equal to itself:
$$ P = P $$
Then, add an appropriate benchmark (B) to, and subtract this benchmark from, the right-hand side of the equation:
$$ P = B + (P − B) $$
The term \(P – B\) is the result of the manager's active management decisions, which we denote as A. Thus:
$$ P = B + A $$
The portfolio return is a function of the benchmark and the manager's active decisions. Next, add market index return (M) to and subtract it from the right-hand side of the equation:
$$ P = M + (B – M) + A $$
The manager's style return is the difference between the benchmark return and the market index (B – M):
$$ P = M + S + A $$
The final equation states that the portfolio return (P) is a result of the market index return (M), a style return (S), and the active management return (A).
If the manager's portfolio is a broad market index where S = 0 and A = 0, then the portfolio earns the broad market return: P = M.
If the benchmark is a broad market index, then S is assumed to be zero and the prediction is that the manager earns the market return and a return to active management: P = M + A.
Question
Assume that an account has a return of 6.9% in a given month, during which the portfolio benchmark has a return of 6.2% and a market index has a return of 3.2%.
Calculate the return due to active management for the account:
- 7.0%.
- 0.7%.
- 3.7%.
Solution
The correct answer is B.
The return due to active management is \(A = P – B = 6.9\% – 6.2\% = 0.7\%.\)
A is incorrect. It misapplies the decimal in the answer as 7.0%.
C is incorrect. It uses the market index return rather than the portfolio benchmark returns \(6.9\% – 3.2\% = 3.7\%.\)
Performance Measurement: Learning Module 1: Portfolio Performance Evaluation; Los 1(k) Discuss tests of benchmark quality