The interaction between unit and item nonresponse in view of the reverse cooperation continuum

The paper addresses two questions. First, is item nonresponse (INR) a precursor of panelattrition (UNR), as predicted by the theory of a latent cooperation continuum, or is theinterrelation of another type? Second, are the results in models of item nonresponse behavioraffected by a selectivity bias due to panel attrition?We test the hypothesis of a latent cooperation continuum with data taken from the GermanSocio-Economic Panel (GSOEP) - and can not find evidence for it.In contrast, we hypothesize that the relationship of both nonresponse types may be inverse inprinciple (the reverse cooperation continuum) and both types of cooperation may coexist.Besides unit nonresponse we analyze questionnaire nonresponse, i.e. participating butrefusing a whole questionnaire with specific items in a multi-questionnaire survey.We find evidence for negative correlation of INR with questionnaire nonresponse. Thecorrelation between item and unit nonresponse is inverse U-shaped which supports thehypothesis of coexistence of both types of cooperation.Addressing the second question we test whether panel attrition causes endogenous sampleselection in regressions of INR by means of a bivariate probit model for selection correction.Additionally we use Monte Carlo simulations to test the influence of alternative assumptionsfor INR-behavior of attriters. The results show that attrition bias is item-specific. Existenceand magnitude of the bias differs with the analyzed subsample.