摘要:AbstractItaly and Spain, as countries of recent immigration and high irregularity rates, have struggled to adapt their statistical system, especially their population registers, to adequately reflect the presence of an increasing number of immigrants in their territory. The population registers of the two countries have adapted differently to these changing realities: Spain introduced significant improvements in Padrón which have increased its coverage and accuracy. This is still not the case in Italy, making it necessary to resort to non-random sampling methods. The paper discusses the methodological implications of these differences and evaluates different methodological solutions based on both random and non-random sampling methods in both countries.