Page 148 - Contributed Paper Session (CPS) - Volume 6
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CPS1851 Hee Young Chung et al.
                  where  =  ( | ) =  +   . Thus, the sample distribution  ( | ) is a
                                                                                       
                                                                                     
                                                1 
                                           0
                                  
                               
                          
                                     
                                                                                  
                  linear  combination  of  population  distributions   ( | )  and   ( | ) .
                                                                                    ∗
                                                                           
                                                                                       
                                                                                          
                                                                                    
                                                                     
                                                                        
                  Therefore, we have the following result:

                                      0              1                        2
                                                                                   1
                                                     1 
                                                                2
                                                                     2
                       ( | ) =   +      +   +      ( +  ) =  +   +  
                       
                                             
                             
                          
                                                                            
                                                                
                                                                                 0
                                   0
                                                                                      1 
                                                  0
                                        1 
                                                       1 
                  Now,  if  we  use    1  2   ≈    1  2     to  simplify  the  calculation  and  let
                                     0 +  1     0 +  1  ()
                                                     
                   ( | ) =  () , then the corrected estimator is as follows.
                         
                      
                   
                               

                                                                  2
                                                                 1
                                                        ()
                                      ( | ) =  =    −     ()                  (10)
                                            
                                                   
                                          
                                       
                                                              +  
                                                              0
                                                                    1 

                  b.    Parameter estimation of linear response rate model
                         The parameters of linear response rate model are estimated by using
                  the following model similarly used in the exponential response rate parameter
                  estimation.
                                             1
                                               =  +   +                      (11)
                                                         1 
                                                   0
                                                                
                                              
                  Therefore,  ,   can be estimated whenever we have the weight   and the
                                1
                              0
                                                                                    
                  data   obtained from the substrata. Here it is assumed that   is independent
                                                                             
                        
                  and identically distributed.

                  c.    The proposed estimator for a given stratum mean
                   (1)  Simple mean estimator
                                                                               
                      Since the weight of a given stratum is constant,  =  =  is used and
                                                                      ℎ
                                                                               
                      the following equation is obtained for mean estimator
                                                ℎ     1     ℎ
                                          1
                                     ̅ ̂
                                      =   ∑ ∑  =  ∑ ∑  =  ̅                (12)
                                                      
                                      
                                                                   
                                          
                                            ℎ=1  =1       ℎ=1  =1
                   (2) Stratified weighted mean estimator
                      Since the weights of the substrata are different, the following mean
                      estimator is used.
                                                        ℎ
                                             ̅ ̂
                                             =  1  ∑ ∑                         (13)
                                             
                                                           ℎ ℎ
                                                    ℎ=1  =1
                   (3) Bias corrected estimator
                                                                        ̂
                                                                   ̂
                      The expected value   () obtained from   ()  =  +    and
                                                                         1 
                                                                    0
                       ̂ ̂
                       ,   obtained from the response rate model (11) are used. The
                          1
                        0
                      proposed estimator is as follows.
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