Estimation of Inputs of Increment - Decrement Cohort Life Table

   This study interested in estimating inputs of Increment - Decrement Cohort Life Table when complete cohort data is available and incomplete cohort data assuming that the risk in each age category is constant and assuming that the relation between the risk of withdrawal from non-absorbing state and its increments in each age categories after developing the definition of increments to absorbing states and handling increments to non-absorbing states from subsequent degrees. Inputs of Increment - Decrement Cohort Life Table were determined by model with two non-absorbing states and one absorbing state within the previous mentioned hypotheses. These inputs were estimated by Maximum likelihood function when complete cohort data or incomplete cohort data is available. The study faced problem of defining likelihood function; in away allow its components to be independent from each other and also problem of defining the probabilities with likelihood function which describes the behavior of the observation in the previous mentioned model. The consistency of these estimates has been approved, despite its biasness in the case of incomplete cohort data. Information matrix was obtained in the general case when incomplete cohort data is available. Variance and co-variance of estimators were obtained in the special case; in the case of existence of increments to non-absorbing states from only the first degree if incomplete cohort data is available.  A simple example was applied include use and non-use of family planning as non-absorbing states and the lost from follow-up as absorbing state.