Ordered categorical responses; The SOCATT data 


Model descriptionThe SOCATT data set is used in the comparison of different software packages for multilevel modelling, conducted by the Centre for Multilevel Modelling. The SOCATT data consist of the responses to a set of dichotomous items on a woman's right to have an abortion. The outcome variable (y_{ij}) is a score constructed from these items ranging from 1 to 7, with a higher score corresponding to stronger support for abortion. Each of 264 respondents was asked the same set of questions on four occasions, 19831986, and y_{ij} denotes the response from individual i in year j. We consider one categorical covariate (religion) with 4 categories. A random intercept ordered logit model was fitted:logit[ P(y_{ij} < s) ] = k_{s} +
b_{1}x_{i1} + b_{2}*x_{i2} + b_{3}*x_{i3} + u_{i},
u_{i} ~ N(0,s^{2})
where x_{1i}, x_{2i} and x_{3i} are dummy variables coding for
the different levels of the categorical covariates, and k_{s} are threshold
parameters. A full description of the model can be found here: socatt.pdfResultsThe following table shows the parameter estimates obtained with ADMBRE.
Results for other software packages can be obtained here. 