(a) Suppose that a researcher has 64 observations on the log stock price indexes of Korea (kt), Japan (t) and Singapore (st). Each of these stock price index series are l(1). The researcher also has 64 observations on the yields of 3-month and 6-month treasury bills for Australia. They are denoted Y3t and Y6t. Both of these series are 1(O). (0) Suppose the researcher decides to estimate the following regression by OLS: Ast = Bo + B14jt + ut Under what circumstances is this an appropriate regression to estimate. Explain your answer fully. (2 marks) (ii) Suppose the researcher estimated the following regression by OLS: jt = Bo + Bikt + ut The autocorrelation function of the estimated residuals was 0.24 at lag 1,0.23 at lag 2, 0.19 at lag 3, 0.16 at lag 4, and continued to decline to zero at subsequent lags. What do you conclude about whether or not this regression gives reliable results about the relationship between the two variables? Explain your answer fully. (2 marks). (iii) The researcher decides to estimate the following regression by OLS: kt = Bo + B1Y6+ + ut Will this estimated regression give reliable results about the relationship between the two variables? Explain your answer fully. (1 mark)