Portuguese regions are quite different regarding several development indicators, such as educational levels, regional value added per capital, purchasing power, and others. The industrialization process followed different models in the northern and southern regions of the country. The persistence of traditional traits - such as the dominance of small scale and family firms, as well as the relevance of informal networks characterizes the northern model. This region is also associated with a slow entrance into the sustained fertility decline that characterized the first demographic transition. The South followed the European demographic trends more rapidly. In this presentation we intend to develop the idea that this demographic delay was important as a factor of disadvantage for regional development in the past, as well as to show that, in contemporary times, a similar effect may be happening, with evidence from the slow entrance of this region into the second demographic transition. Secondary demographic data is used to show the different timing of demographic changes at a regional level. Original survey data from the northwestern region (n=214, conducted in 2008) are presented to show how family size has changed during last decades and how it interacts with other socioeconomic and territorial factors, such as education, social class, rural or urban contexts. Desired family size and actual family size are also measured. The sustained and voluntary reduction of fertility is a demographic trend that accompanies regional development, revealing changes in societal values, in the perceived chances of survival of children, and in the economic opportunities and goals of individuals and families. Late demographic change in the northwestern Portuguese region is confirmed by our comparative analysis as a persistent trait of this region, and accompanies others such as low levels of educational investment per child, low levels of educational attainment among young people, and the persistence of emigration. We conclude that the persistence of high fertility levels during first demographic transition was one of the more relevant factors of such traits. More recently, northwestern families are less prone than other regions families to adopt the demographic changes that characterize the second demographic transition. Our original data show that lowest-low fertility has started to emerge as a pattern of family behavior. Individuals would like to have more children, but they decide not to do so in order to ensure a better life and the resources to achieve more ambitious life chances.
