Mplus Users Guide v6.. - Muthén & Muthén

TITLE, DATA, VARIABLE, And DEFINE Commandscategories of a four-category nominal variable are referred to as u1#1,u1#2, and u1#3.The estimation of the model for unordered categorical dependentvariables uses zero to denote the lowest category, one to denote thesecond lowest category, two to denote the third lowest category, etc. Ifthe variables are not coded this way in the data, they are automaticallyrecoded as described below. When data are saved for subsequentanalyses, the recoded categories are saved.Following are examples of situations in which data are recoded by theprogram:Categories in Original DataCategories in Recoded Data1 2 3 4 0 1 2 32 3 4 5 0 1 2 32 5 8 9 0 1 2 30 1 no recode needed1 2 0 1COUNTThe COUNT option is used to specify which dependent variables aretreated as count variables in the model and its estimation and the type ofmodel to be estimated. The following models can be estimated for countvariables: Poisson, zero-inflated Poisson, negative binomial, zeroinflatednegative binomial, zero-truncated negative binomial, andnegative binomial hurdle (Long, 1997; Hilbe, 2007). The negativebinomial models use the NB-2 variance representation (Hilbe, 2007, p.78). Count variables may not have negative or non-integer values.The COUNT option can be specified in two ways for a Poisson model:COUNT = u1 u2 u3 u4;orCOUNT = u1 (p) u2 (p) u3 (p) u4 (p);or using the list function:491