The fertility decline in the industrial area of Charleroi during the second half of the 19th century. Did sedentary and migrant people have a different behaviour?

The aim of this analysis is to compare the fertility strategies adopted by migrant and sedentary couples in the industrial crisis context of the last quarter of the nineteenth century. What was their level of fertility before, during and after of the period of the industrial crisis? Who were the forerunners of the fertility decline? And when the decline started, were the control strategies of these two populations the same?