BICOP: a Stata command for fitting bivariate ordinal regressions with residual dependence characterised by a copula function and normal mixture marginals

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Understanding Society Working Paper Series


Monica Hernandez-Alava and Stephen Pudney

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This article describes a new Stata command, bicop, for fitting a model consisting of a pair of ordinal regressions with a flexible residual distribution, with each marginal distribution specified as a two-part normal mixture, and stochastic dependence governed by a choice of copula functions. The bicop command generalizes the existing biprobit and bioprobit commands which assume a bivariate normal residual distribution. The command and post estimation options are presented and explained with an illustrative application to data on financial wellbeing from the UK Understanding Society Panel Survey.

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