Who has won Rugby Union World Cups, and why? A sequential approach based on multinomial probit

Final economic outcomes are often determined over consecutive process stages. The most prevalent approach is to model inter-nodal transition/event probabilities using techniques such as sequential logit. Transition success for survivors at each stage is then regressed on explanatory variables using standard logit (allowing for correlation in the error-terms). This seemingly un-related approach benefits from methodological convenience. It crucially depends, however, on the assumption that at each stage, any un-observable factors are independent. We believe that error term independence may often be an excessively strong assumption. We propose an alternative approach based on multinomial probit that does not rely on that very restrictive assumption. Implementation is no more demanding. We describe the procedure using Stata 13. To illustrate the usefulness of the method, we estimate the determinants of success for each stage at the Rugby World Cup.