Section 8 Box 6: Estimate clever covariate \(H\)

# clever covariates
ObsData$H.A1L <- (ObsData$A) / ObsData$PS.SL 
summary(ObsData$H.A1L)

##        V1         
##  Min.   : 0.0000  
##  1st Qu.: 0.0000  
##  Median : 0.0000  
##  Mean   : 0.8986  
##  3rd Qu.: 1.4812  
##  Max.   :71.3503

boxplot(ObsData$H.A1L)

ObsData$H.A0L <- (1-ObsData$A) / (1- ObsData$PS.SL)
summary(ObsData$H.A0L)

##        V1        
##  Min.   : 0.000  
##  1st Qu.: 0.000  
##  Median : 1.078  
##  Mean   : 0.957  
##  3rd Qu.: 1.392  
##  Max.   :14.777

boxplot(ObsData$H.A0L)

ObsData$H.AL <- ObsData$H.A1L - ObsData$H.A0L
summary(ObsData$H.AL)

##        V1           
##  Min.   :-14.77746  
##  1st Qu.: -1.39225  
##  Median : -1.07847  
##  Mean   : -0.05846  
##  3rd Qu.:  1.48121  
##  Max.   : 71.35033

boxplot(ObsData$H.AL)