Tese de Doutorado
Transição e tendências da disponibilidade de irmãos para o Brasil: um estudo metodológico sobre relações de parentesco
Fecha
2014-08-25Autor
Francismara Fernandes Guerra Silva
Institución
Resumen
When fertility declines, it is not only the number of children becoming smaller, but also the number of siblings (MURPHY, 2010). This structural change of the family raises the concern of studies that examine the family in terms of size and existence of siblings. To determine the changes on the number of siblings in Brazil, seen the recent low levels of fertility, we employ the method developed by Goodman, Keyfitz and Pullum (1974), which is designed to estimate the expected number of siblings through mathematical models that use only rates of fertility and mortality, as well as we develop and apply our own models to estimate the distribution of the number of siblings, adopting the same principles and data. We use the rates built by Horta, Carvalho and Frias (2000) and Wajnman (2012) based on various demographic data released by Instituto Brasileiro de Geografia e Estatística (IBGE). Our results indicate that, at the beginning of the demographic transition in Brazil, the mean of born siblings settles at high levels, suffers a sharp decline during the process, mainly driven by the decline in fertility, and is currently setting at low levels. At the same time, we see oscillations in the mean of alive siblings during this process, culminating in a gentle decline, and the difference between the initial and final means found is small, given that the initial levels of expected number of alive siblings were already at lower levels. There is clear convergence trend between mean of children and mean of siblings, born and alive, and in this latter case, because of increased survival. The (re)distribution of the number of siblings shows significant and growing concentration of population in small families with only one or no sibling. We conclude that, although the verticalization of the family is observed through the decrease in the mean of number of siblings (born) and the increase in the proportion of singleton, the possibility of extinction of the siblings is far from being considered a next trend for Brazil because a significant share of the population tends to have at least one sibling.