The median country went from six births to two in fifty years

How much did each country's fertility fall between 1960 and 2011? Each row is one of twelve countries with its total fertility rate at both ends of the period and the difference between them. Every one of the twelve fell. The size of the fall depended almost entirely on where a country started.

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Twelve lines, all sloping down

Each line joins a country's 1960 rate to its 2011 rate. The median country's rate was 6.01 births per woman in 1960. By 2011 it was 2.14. Nine lines start above five and plunge; the three that start low, in France, Japan, and the United States, barely tilt. One high line stays high: Nigeria's.

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Korea fell by almost five births; Nigeria by a third of one

Each bar is a country's change over the period, with the mean marked. The average change was -2.97 births per woman. Korea's change was -4.91 births per woman, the largest fall of the twelve. Nigeria's was -0.34, the smallest.

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The higher the start, the bigger the fall

Each dot is one country, placed by its 1960 rate and its change. The fitted line slopes down: the correlation between the 1960 rate and the change was -0.70. The nine countries that started above five births fell by an average of -3.60 births per woman. The three that started below four fell by -1.06. Nigeria sits alone at the top right, high start and no fall.

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Takeaway

Where fertility was high in 1960 it fell far, and where it was already low it had little room to fall. The one country that broke the pattern, Nigeria, started high and stayed there, so the size of a fall says little about where a country ends up.

Limits

Two readings per country: the route between them, including reversals, is invisible here. Twelve countries chosen for contrast, each weighted equally. The period ends in 2011 because later years are blank in this export.