Feedback mechanisms in the postponement of fertility in Spain

In this chapter we describe the process of fertility postponement initiated in Spain in the mid-1970s using a dynamic model that considers the interaction of four main factors. Rising economic uncertainty and the expansion of higher education provide the original impulse which is later amplified by the feedback generated via social interaction as young men and women start imitating the behavior of their peers and friends. As the pressure to conform to an early family formation standard is reduced, the postponement process gains momentum. This multiplier effect explains a substantial part of the observed trend, but its pace and extent also depend on the resistance exerted by social norms. Our model tries to capture the dynamic mechanism by which norms shape behaviors and behaviors shape norms, in a process of mutual dependence. This feedback loop between individual actions and aggregated outcomes allows us to bridge the micro and macro levels of analysis and it proves to be a key element in the explanation of the massive and ongoing transformation of fertility patterns in Spain in the last decades.