Achieving sustainable population: Fertility decline in many developing countries follows modern contraception, not economic growth

Abstract The human population is projected to increase by 2.4 billion 2100, endangering, for example, food security and biodiversity. Population growth depends strongly on fertility level, lowering of which often assumed depend economic growth. Here we test this hypothesis using data from 136 developing countries, 1970–2014. We formed four country groups at different initial economy, used graphical analyses, with estimates variation. Falling rates 1970–2000 showed little or no association economy (GDP household consumption). Fertility decreased regardless whether the grew, was stagnant, declined. But falling closely associated increasing use modern contraception, largely independent changes in economy. decline hence not caused development, but followed contraceptive use. Family planning programs, advice family size offer promising routes sustainably low where it has yet been achieved.