AbstractFertility levels have decreased greatly in virtually every nation, but the timing of the decline has differed even among developed countries. In Europe, Asia and North America, total fertility rates (TFRs) of some nations dipped below the magic replacement figure of 2.1 as early as the 1970s. But in other nations, fertility rates remained substantial until the 1990s, plummeting subsequently. This paper addresses why some countries in Europe and Asia with moderate fertility levels in the 1980s have become the ‘lowest low’ nations today (TFRs less than 1.3), whereas those that decreased earlier have not. Also addressed is why the crossover point for the two groups of nations was around the 1980s and 1990s. An important factor that distinguishes the two groups is their economic growth in the decades after the Second World War, especially the 1960s and 1970s. Countries with ‘lowest low’ fertility rates today experienced rapid growth in GDP per capita after a long period of stagnation or decline. They were catapulted into modernity, but the beliefs, values and traditions of their citizens changed more slowly. Thus swift economic change may lead to both generational and gendered conflicts that result in a rapid decrease in TFR.