Based on an extended game-theoretic innovation-race model, we derive some Schumpeterian hypotheses of the impact of technological rivalry, market power, technological opportunities and market size on the timing of product and process innovations. Using innovation data at the firm level in the...

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...

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 model of firms' optimal R&D behavior under financial constraints, we estimate...

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...