Managing Autocorrelation - Adding Predictors - Example 1 (R)


Notes and Considerations

 
Montgomery CH03 Example 3.13 p. 139

Output, along with R script, is included in the file "CH03 Example 3-13 manage autocorrelation with additional predictor.docx" attached below.

Example of how, in some situations, adding another predictor (explanatory variable) to a linear model can reduce autocorrelation in the model residuals.


Also includes comparison of R functions for checking autocorrelation using Durbin-Watson
  • Shows possible inconsistency of durbinWatsonTest() function (car package) and provides an alternative using the 'dwtest()' function from the lmtest package.



Data Set

 
Tables 3.13 & 3.15 soft drink concentrate sales data


Data is also included in the R script file attached below.



Analysis or Script File

 
See the file "CH03 Example 3-13 manage autocorrelation with additional predictor.R" attached below.




Comments