Can anyone help me solve problems about Absolute and Relative Purchasing Power Parity ?

CFA Level II
#1

  1. Compare and explain the Absolute and Relative Purchasing Power Parity of exchange rates(APPP and RPPP). How to build these models to test APPP and RPPP, respectively? If the error terms are i.i.d, the estimators are the BLUE(Best Linear Unbiased Estimator) in above estimations? 4. The Forward Exchange rate is the unbiased estimator of the future spot exchange rate(Unbiased Hypothesis)? Even if the error terms are i.i.d, the unbiased hypothesis is rejected, explain the reasons why?

  2. The Forward Exchange rate is the unbiased estimator of the future spot exchange rate(Unbiased Hypothesis)? Even if the error terms are i.i.d, the unbiased hypothesis is rejected, explain the reasons why?

I am struggling for solving these 2 questions…Please