g3r41d wrote:
sabiran wrote:
In the CFA text the formula is for each market : (weight portfolio - weight benchmark) x Benchmark return (page 213, book 6).
however in example 6 it looks like they calcute it using (weight portfolio - weight BM) X (return portolio - return BM).
So which one to use? Or will they yield the same result?
In case some of you have not got it yet, in fact both the formulas for (micro attribution) pure sector allocation and (global performance attribution) market allocation contribution are the same except for one small difference stated in bold below.
pure sector allocation: sum (portfolio weight for sector i - benchmark weight for sector i) X (benchmark return for sector i -
benchmark return)
market allocaion contribution: sum (portfolio weight for sector i - benchmark weight for sector i) X (benchmark return for sector i)
In fact whether you put in the benchmark return figure or not does not impact your calculations. Both formulas will yield the same result, because benchmark return is a constant figure, sum (bechmark weight for sector i X benchmark return for sector i).
pure sector allocation = sum (portfolio weight for sector i - benchmark weight for sector i) X (benchmark return for sector i -
benchmark return)
= sum (portfolio weight for sector i - benchmark weight for sector i) X (benchmark return for sector i)
+
[[ sum (portfolio weight for sector i - benchmark weight for sector i) X (benchmark return) ]]
(above term in italics sums to 0)
= sum (portfolio weight for sector i - benchmark weight for sector i) X (benchmark return for sector i)