Professional Trajectories of Workers Using Disconnected Self-Organizing Maps

Using the Panel Study of Income Dynamics (PSID) collected on the period 1984-2003, we study the situations of American workers with respect to employment. The data include all heads of household (men or women) as well as the partners who are on the labor market, working or not. They are extracted from the complete survey by computing a few relevant features which characterize the worker's situations. To perform this analysis, we suggest to use a Self-Organizing Map (Kohonen algorithm) with speci c topology. In this paper we present a new topology for SOM based on a planar graph with disconnected components (called D-SOM) which is especially interesting for clustering. Each component takes the form of a string and corresponds to an organized cluster. From this clustering, we study the dynamics at the individual level, that is the trajectories of the individuals among the classes during the observed period. Then we estimate the transition probability matrices for each studied year and the corresponding stationary distributions. Finally, we try to give an answer to the question: is there a signi cant change in 1992 (new economic policies after the Reaganomics).