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.

Number of categories, Ordered regression model
hdl.handle.net/1765/573
Econometric Institute Research Papers
Report / Econometric Institute, Erasmus University Rotterdam
Erasmus School of Economics

Franses, Ph.H.B.F, & Cramer, J.S. (2002). On the number of categories in an ordered regression model (No. EI 2002-15). Report / Econometric Institute, Erasmus University Rotterdam. Retrieved from http://hdl.handle.net/1765/573