Nº 31 (January, 2006). Luis Casanova. 

Between 1998 and 2002 there was an increase of almost 30 percentage points in the incidence of poverty. To explain this increase an analysis of poverty must be complemented using tools to determine which groups are most vulnerable to enter into a situation of deprivation. The aim of this study is to identify factors that determine the entry, exit or stay in a situation of poverty, and to distinguish between chronic and transitory poverty. The results show that individuals living in households whose head has a low human capital, female-headed households, those where the head has an unstable employment or are unemployed, or in households where the number of income earners is low in comparison to the number of household members are more likely to be structurally poor. Finally, there are sharp regional differences, being the northern regions of the country those that present major problems of structural poverty.