We show that there is no formal statistical testing method to combine categories in a standard ordered regression model. We discuss practical implications of this result.

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hdl.handle.net/1765/573
Econometric Institute Research Papers
Report / Econometric Institute, Erasmus University Rotterdam
Erasmus School of Economics

Franses, P. H.& Cramer, M. (2002). On the number of categories in an ordered regression model. In Report / Econometric Institute, Erasmus University Rotterdam (EI 2002-15).http://hdl.handle.net/1765/573