Difference between revisions of "Durbin-Watson"

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==Assumptions==
 
==Assumptions==
1. The error terms are independent of each other.
+
The error terms are independent of each other.
  
 
*The Durbin-Watson test uses the following statistic:
 
*The Durbin-Watson test uses the following statistic:
 
<math>d=\frac{\sum_{i=2}^n (e_i-e_{i-1})^2)}{\sum_{i=1}^n (e_i)^2}</math>
 
<math>d=\frac{\sum_{i=2}^n (e_i-e_{i-1})^2)}{\sum_{i=1}^n (e_i)^2}</math>
where the <math>e_i = y_i-\bar{y_i}</math>
+
* where the <math>e_i = y_i-\bar{y_i}</math> are the residuals
 +
* n is the number of elements in the sample
 +
* k is the number of independent variables

Revision as of 05:48, 3 May 2017

DURBINWATSONTEST(DataRange,ConfidenceLevel,NewTableFlag))


  • is the array of x and y values.
  • is the value of alpha from 0 to 1.
  • is either TRUE or FALSE. TRUE for getting results in a new cube. FALSE will display results in the same cube

Description

  • This function gives the test statistic of the Durbin-Watson test.
  • The test is used to detect the presence of autocorrelation in the residuals.
  • Autocorrelation means that adjacent observations are correlated.
  • If they are correlated, then least-squares regression underestimates the standard error of the coefficients.

Assumptions

The error terms are independent of each other.

  • The Durbin-Watson test uses the following statistic:

  • where the are the residuals
  • n is the number of elements in the sample
  • k is the number of independent variables