CAPP_DYN© is a dynamic micro-simulation model based on heterogeneous population.The model uses probabilistic simulation to forecast the main demographic (birth, marriage, divorce, death) and economic (education, access to the labour market, occupational status, retirement) trends of a given population in a given year (e.g. 2002). The model has a recursive structure and thus, provides the projection for a given population in a given year until 2050 (in other w ords, over the period 2002-2050). This allows the analysis of the long-term redistributive effects of the social security system along with its reforms, with a particular focus on pensions and long-term care. The heterogeneity of the population for each year of the simulation allows the estimation of both intra- and intergenerational effects of the welfare reforms taken into consideration for the study.