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西红柿面 · 2024年06月04日

B为什么不对?

NO.PZ2023040502000024

问题如下:


The results reported in Exhibit are most accurately interpreted as indicating that:

选项:

A.

multicollinearity is not present.

B.

the reported R2 is spurious.

C.

the regression coefficients have inflated standard errors.

解释:

The pairwise correlation is low. The only case in which correlation between independent variables may be a reasonable indicator of multicollinearity occurs in a regression with exactly two independent variables, as is the case in this problem. Furthermore, the additional classic symptoms of multicollinearity (high R2and significant F-statistic but not significant coefficients) are not present.

  1. B为什么不对?
  2. DW检验的值大于Critical Value,说明有Autocorrelation,这个理解对吗?
1 个答案
已采纳答案

品职助教_七七 · 2024年06月05日

嗨,努力学习的PZer你好:


1)spurious R方是多重共线性的特征之一。本题没有多重共线性,也就不会有B选项的现象存在;

2)DW test的做法教材已经删除了,本题也不是考察DW test和autocorrelation的,仅做简单说明如下:

DW test是否拒绝原假设的结论可参考下图。DW critical value有两个,本题分别是dl=1.63和du1.72。由于DW

statistic=1.89,超出了这个范围且靠近2,所以不能拒绝原假设。说明没有serial correlation的问题。

上面讲解和下图都仅供参考,现在已经不这样考了。


 

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