Unveiling Mexico's Demographic Transitions.

This study examines Mexico's fertility transition (1930-2015) and how socioeconomic status (SES), geography, and indigeneity shaped reproductive behaviors. Using net fertility-the number of surviving children under five-we assess how prestige bias (adopting high-status fertility norms) and conformism bias (aligning with local norms) influenced change across distinct population groups. We introduce the time, space, and population model to analyze the combined effects of macrostructural forces, spatial diffusion, and individual decision-making. Our spatial analysis reveals a concentric diffusion pattern, where fertility changes spread outward from urban, high-SES municipalities. Findings reveal a consistent negative association between SES and fertility across all periods, though with varying intensity. Higher status populations led the fertility decline, but patterns differed by group and over time. Fertility declined at different rates across four groups: urban non-Indigenous populations transitioned rapidly, rural non-Indigenous groups stagnated, rural Indigenous populations experienced delays, and urban Indigenous groups resisted fertility decline. Evidence suggests non-Indigenous populations regulated fertility through retarding marriage before widespread contraceptive adoption, while Indigenous groups followed more conformist behaviors. This study integrates historical demographic data into a structured framework, improving research on long-term fertility transitions.