Nittner, T. and Toutenburg, Helge
Identifying Missing Data Mechanisms in (2 x 2)-Contingency Tables.
Collaborative Research Center 386, Discussion Paper 373
Consider the sample of two binary variables X and Y with some missing structure within X or Y. The knowledge about the corresponding values of the observed covariate allows to play through all possible `originally' complete data sets. After defining the notation, including some theoretical work, a test for non--MCAR within the complete case table is presented. Simulating all possible tables enables some testing on non--MAR. A simulation experiment is used to illustrate this context.