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Collinearity is concerned with linear relationships among the X variables. linea

ID: 3220228 • Letter: C

Question

Collinearity is concerned with

linear relationships among the X variables.

linear relationships in the error term.

the correlation between Y and b1.

transformations made to Y.

Question 2

Which of the following can occur if collinearity is a problem?

Question 3

The variable X1=Household Income was one of 5 X variables being used in a regression analysis. When Household Income was used as the dependent variable and the other 4 X variables were used as the independent variables the resulting model had an R2 of 0.75.

What is the Variance Inflation Factor for Household Income?

Question 4

Principal Component Analysis produces linear combinations of the X variables that are uncorrelated.

linear relationships among the X variables.

Explanation / Answer

1)Linear relationships among the X variables.

Correlation between independent variables causes Collinearity

2)The standard error of the estimates of the coefficients of the X variables will be large. A significant relationship can be hidden.

MULTI-co-linearity increases SE, which makes some coefficients statistically insignificant when infact they are significant.

3) VIF = 1/(1-R^2) = 1/(1-.75) = 1/.25 = 4

4)

TRUE. Principal Component Analysis uses correlation structure of original variables and derives linear combinations which are uncorrelated.