I have been discussing the definitions of MAR and MCAR with others. Data missing by design is an example of MCAR that is given often in the literure. Some think this is not an example of MCAR, but an example of MAR.
>From my understanding of the definition of MCAR, data is MCAR if (1) P(R| Y, Z) = P(R |Z) where Y = complete data matrix, R = missing data indicator matrix for Y, Z = matrix of conditioning covariates,experimental treatments, and other design variates. Hence, the above example is MCAR. However, my colleagues think that (1) is the definition of MAR. and the definition of MCAR is (2) P(R|Y,Z) = P(R). In this case, the above example is not MAR. In the presence of conditioning covariates, and design variates, what is the definition of MCAR? Thanks, Dionne
