Picture: Getty Images

There’s almost nothing more important than fertility in determining a nation’s future viability.

Demographers suggest that a country needs a fertility rate of just over two children per woman to hit “replacement fertility” — the rate at which new births fill the space left behind by death.

But due to certain cultural and economic forces, only about half of the world’s 224 countries currently hit replacement fertility.

For them, encouraging people to have sex can involve strategies that range from the highly explicit to the downright bizarre.

Is that Boyz II Men I hear?

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