The threshold hypothesis: evidence from less developed Latin American countries, 1950 to 1980.

Historical research among European countries finds large differences in the level of social, economic or demographic development among countries, or regions within countries at the time marital fertility rates began their decline from traditional high levels. This research tests a threshold hypothesis which holds that fertility will decline from traditional high levels if threshold levels of life expectancy and literacy are surpassed. Using a pooled regression analysis of 1950, 1960, 1970 and 1980 crude births rates (CBRs) in 20 less developed Latin American countries, in conjunction with 10-year lagged measures of social, economic and family planning program development, analyses reveal statistically significant effects of passing Beaver's (1975) threshold levels of 1950 literacy, or 1950 life expectancy, that are independent of levels of lagged literacy (or lagged life expectancy), economic and family planning program development, as well as measures that control period effects.