* Encoding: windows-1252.
*SYNTAX FOR SCHNAPP, SENSITIVE QUESTION TECHNIQUES AND CARELESS RESPONDING: ADJUSTING THE CROSSWISE MODEL FOR RANDOM ANSWERS.

use all.
weight off.
split file off.

*New variable age.
compute AgeApprox = 2018 - YearOfBirth.
execute.

*n filtering out only respondents who did not answer first companion question.
*Filter.
DATASET ACTIVATE DatenSet1.
USE ALL.
COMPUTE filter_$=( ~missing(Castleman_CM)).
VALUE LABELS filter_$ 0 'Not Selected' 1 'Selected'.
FORMATS filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE.

*n.
fre var=id_user.


*Filter out  respondents who did not answer first companion question or said they (may have) answered questionnaire before.
*IMPORTANT: This filter must be switched on for all following analyses or they will yield incorrect results.
DATASET ACTIVATE DatenSet1.
USE ALL.
COMPUTE filter_$=((missing(AnsweredBefore) | AnsweredBefore = 0) & ~missing(Castleman_CM)).
VALUE LABELS filter_$ 0 'Not Selected' 1 'Selected'.
FORMATS filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE.

*n.
fre var=id_user.

*Sociodemographics.
*IMPORTANT: SPSS yields incorrect standard deviations for proportions. Standard deviations were calculated by hand as SQUARE ROOT((PROPORTION*(1-PROPORTION))/N).
descriptives variables = 
YearOfBirth
Abitur
Gender
AgeApprox.

*CM variables recodes.
recode Castleman_random (2=0) (else=copy) into CastlemanDummy_random.
recode Chagas_random (2=0) (else=copy) into ChagasDummy_random.
recode Barth_random (2=0) (else=copy) into BarthDummy_random.
do if ~missing(Castleman_random).
recode Castleman_CM (2=0) (else=copy) into CastlemanDummy_CM.
end if.
do if ~missing(Chagas_random).
recode Chagas_CM (2=0) (else=copy) into ChagasDummy_CM.
end if.
do if ~missing(Barth_random).
recode Barth_CM (2=0) (else=copy) into BarthDummy_CM.
end if.
execute.

*Compute CM_adj variables.
compute CastlemanDummy_CMadj = 0.5*CastlemanDummy_random + CastlemanDummy_CM*(1-CastlemanDummy_random).
compute ChagasDummy_CMadj = 0.5*ChagasDummy_random + ChagasDummy_CM*(1-ChagasDummy_random).
compute BarthDummy_CMadj = 0.5*BarthDummy_random + BarthDummy_CM*(1-BarthDummy_random).
execute.

*Input for Estimates: SCM and CMR-S.
FREQUENCIES VARIABLES=CastlemanDummy_random ChagasDummy_random BarthDummy_random CastlemanDummy_CM 
    ChagasDummy_CM BarthDummy_CM 
  /ORDER=ANALYSIS.

Input for estimates: CMR-I (sum of adjusted "A" answers).
descriptives variables = CastlemanDummy_CMadj ChagasDummy_CMadj BarthDummy_CMadj
/statistics = sum.