Legislative productivity is a crucial factor in evaluating the effectiveness of representative democracies. To investigate the link between government ideology and legislative activities, we analyze the production of five legislative instruments by the Italian parliament from March 1994 to February 2018, using a Bayesian non-parametric model which relies on a hierarchical normalized generalized gamma prior. Through a natural creation of clusters, this model allows comparisons within and between different legislative instruments. This approach allows us to investigate whether different governments change their legislative productivity at the end of the government period, if differences emerge in the governments’ production of different legislative instruments and how such differences are linked to governments ideology.