Dynamics of Morphological Productivity. A Synchronic Analysis and Diachronic Explanation of the Productivity of Nominal Inflection Classes from Archaic Latin to Old Italian in Terms of Natural Morphology. (xiii, 575 pp.)

The present dissertation is a theoretical synchronic and diachronic study on inflectional productivity with empirical work on language data from Latin throughout its history and from Old Italian.
Given the central role of productivity for morphological theory, a wealth of discussions has been conducted on the topic within the most different frameworks. Yet, productivity still remains one of the most controversial issues in current linguistic trends. Particularly, very little of work has been done in the literature on productivity of inflectional classes and rules from a diachronic perspective.
The theoretical framework of the present thesis is the model of inflection morphology of Natural Morphology as developed by Dressler.
This approach represents a new theoretical, empirical and methodological account of tracing changes in inflectional diachronic productivity.
Within this model productivity is assumed to be a constitutive primitive property of inflectional patterns and assigned to the level of grammatical competence, thus distinguished from type and token frequency. Furthermore morphological productivity is viewed as gradual.
In order to measure the degrees of productivity of the nominal inflection of Latin and Old Italian, a hierarchical scale of criteria, originally proposed by Dressler and now presented in a thoroughly modified outline, is applied.
The present work establishes an innovative theoretical basis for viewing productivity from an evolutionary and typological perspective which can be operationalised through the measurement of productivity over time in historical corpora. The thesis overcomes a striking gap in linguistic research by exploring diachronic changes in inflectional productivity and detecting the role of typological shift in the process of increase and decrease of morphological productivity in inflection systems.