孫同學(xué)
2018-10-18 23:022、對于AR(P)的模型,記得周琪老師的視頻是說,從Xt-1、Xt-2一直試到Xt-p,看到底從滯后多少期P開始r(Xt-p,Y)=0,就用到AR(P);但是比如原本書后題目第4題B答案:we should first estimate an AR(1) model and test to see whether the residuals from this model have significant serial correlation. If the residuals do not display significant serial correlation, we should use the AR(1) model. If the residuals do display significant serial correlation, we should try an AR(2) model and test for serial correlation of the residuals of the AR(2) model. We should continue this procedure until the errors from the final AR(p) model are serially uncorrelated. 說的又是看殘差從哪一期開始沒有自相關(guān),如果沒有就用到AR(P),這個(gè)AR(P)到底是啥意思?
所屬:CFA Level II > Quantitative Methods 視頻位置 相關(guān)試題
來源: 視頻位置 相關(guān)試題
1個(gè)回答
Vincent助教
2018-10-21 20:28
該回答已被題主采納
同學(xué)你好,序列自相關(guān)是從殘差項(xiàng)t 與 滯后所有殘差項(xiàng)做相關(guān)系數(shù)檢驗(yàn),如果有一個(gè)顯著,說明有序列自相關(guān)。需要在模型后加上一個(gè)滯后項(xiàng),
從AR(1),變成AR(2)
AR(P) 表示有滯后p個(gè)滯后項(xiàng)來解釋當(dāng)前的我,比如AR(3), 說明是滯后一期,滯后兩期和滯后三期來解釋今天的我
