Performanace Evaluation

Vol 6 page 243 Eoc # 12; they are asking - poor security selection in which country?

Here in the answer they have included interaction effect also? Is this always the case ?

In #10,#11 and #12, they consistently define Allocation = (wi - Wi)(Bi - B) which contradicts with the Brinson Model which is (wi - Wi)Bi.

To put it in another way, in the exercises, the allocation + selection + interaction doesn’t even add up to wR - WB, which is clearly wrong to me.

My thought is that they misdefined allocation in the exercises (the selection+interaction is defined correctly)

so confused!!