The size and shape of the Italian interest system between the 1980s and the present day

Within interest group research, scholars following the population ecology perspective mainly look at the demographic features of populations and systems under scrutiny: density and diversity represent the main dimensions investigated. Even though, in recent years, an impressive amount of literature on this topic has been produced, there has been neither systematic analysis of, nor empirical research into, the Italian interest system so far. This article aims to address this lacuna. Following a diachronic perspective, we count how many politically active groups have populated the Italian interest system with regard to two different periods: 1984–88 and 2010–14. From 1984 to 2014 the number of interest groups almost doubled and the density of the system greatly increased; diversity, however, has remained relatively more stable.