4.3.3. Independence of the errors (lack of auto correlation of residuals)
The independence of the errors assumption states that there is no dependency relationship between the residuals of the regression model, i.e. the residuals are independent of each other. The Durbin-Watson (DW) statistic was used to test for the presence of correlation among the residuals. In both cases (OGP and FOM), the value of DWis close to 1.5
(DWOGP = 1.53 and DWFOM =1.43), showing little room for improvement in the two regression models, due to
a low correlation in the residuals. However this is too low to be considered a threat and therefore does not justify the effort for changes to the models.