The INE is committed to the quality control secured of the last two censuses of the Portuguese population which assure the use of the final results without reservation. In this article we tried to understand the specific dynamics of the Portuguese population in the last decade of the twentieth century. For so, we used the census data (adjusted to the respective coverage rates), crossing it with the population movement at the level of micro demographic variables.

keywords: data quality, Census 1991, Census 2001, net coverage rate, coverage errors, natural increase, net migration, live births, deaths, balance equation, life expectancy, micro demographic variables, ageing