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 microeconometrics for the dependent variable. It is shown that using ordinal...

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 on the joint distribution for the latent variables which in this case is...

The simple Ricardian model explains the comparative cost advantage by a relative productivity advantage of the single factor of production. This model is tested in this paper using microdata of the german business survey. In a first approach labour is being considered to be the only factor of...