Formulation of a unitary indicator of language competence and use for the evaluation of language policies

Abstract

This paper formulates a unitary indicator of language skills and uses (Ε) that takes into account both the rate and the number of individuals in a territorial unit. First, it reviews a simple model of the relationship between competence and use, which opens up the possibility of a consideration of linguistic entropy and presents a singularity that can be interpreted as a cusp catastrophe. It then adapts Boltzmann’s well-known entropy formula and solves some practical calculus problems. Lastly, it calculates the indicator for the data on home and public use of Valencian (2005-2021) and shows the trend of increasing entropy.