With rapid economic growth of manufacturing and services and urbanisation, however, the circumstances differ to those that typically apply in low income countries in the early stages of development. The difference lies above all in rural labour. Labour is often abundant in rural areas of low-income countries in the early stages of development, but that becomes ever less so, owing to changes in both demand and supply of labour. Demand increases from more intensified forms of farming, from a growing rural non-farm economy – partly stimulated by agricultural growth, and from the jobs on offer in the urban economy. 

On the supply side, while the demographic transition is usually delayed in rural areas compared to urban areas, falling fertility, seen almost universally in the last fifty years in rural areas, means that sooner or later the natural growth of rural populations slows and eventually reverses. In thirteen out of sixteen developing countries, census data show that infant cohorts of 0 to 5 years of age were smaller in the late 2000s and early 2010s than before.