  This research presents an analysis of the demographic risk related to future
membership patterns in pension funds with restricted entrance, financed under a
pay-as-you-go scheme. The paper, therefore, proposes a stochastic model for
investigating the behaviour of the demographic variable "new entrants" and the
influence it exerts on the financial dynamics of such funds. Further
information on pension funds of Italian professional categories and an
application to the Cassa Nazionale di Previdenza e Assistenza dei Dottori
Commercialisti (CNPADC) are then provided.
