Logic Question: In a country in which people only want boys...

[AB Editor]

In a country in which people only want boys, every family continues to have children until they have a boy. If they have a girl, they have another child. If they have a boy, they stop. What is the proportion of boys to girls in the country?

[Mosaic]

Not quite what happens in reality. Countries that prize boy children tend also to be poor or emerging countries. In poor countries girl children are often disposed of by murder, sale or neglect (what the ancient Romans termed 'exposure'). In wealthier areas / emerging countries ultrasound scans are used to detect and abort unwanted female foetuses. No idea what the proportions of surviving boys to girls are though. You'd have to go through data country by country to pick out the patterns. China would be your best starting point, where the ;one child; policy has led to a skewing of the population profile since the late 1960s.

[factor-fiction]

answer is always 50-50 isn't it?

[dr b]

yes, assuming there's a 50/50 chance of having a boy or girl. If there are 100 families you start with 50 boys/50 girls. the 50 who had girls try again, resulting in 25 boys/25 girls. etc etc (make the starting population large enough to avoid fractional kids!).