The polychoric correlation is an ML estimator for the correlation parameter between two latent variables. Each latent variable is only observed as an ordered categorical indicator. This estimator is based on an assumption ...

Using newly available data at the firm level, this study provides convincing evidence of the importance of financial constraints in explaining the timing of innovations in the German services sector. Based on a dynamic ...

This paper investigates the effects of ordinal regressors in linear regression models. Each ordered categorical variable is interpreted as a rough measurement of an underlying continuous variable as it is often done in ...