[derefr]

People have been working white-collar jobs indoors behind UV-reflective windows for 50+ years now. Birth-rate decline — especially to below-replacement levels — begins much more recently than that; and is only happening in certain countries.

The set of countries experiencing birth-rate decline is not 1:1 correlated with the set of countries with high/increasing white-collar employment; but, AFAICT, it is 1:1 correlated with the set of countries that have strong avoidance of tanning / strong interest in skin-whitening.

[whyoh]

>but, AFAICT, it is 1:1 correlated with the set of countries that have strong avoidance of tanning / strong interest in skin-whitening.

I'm not seeing that. The countries that are most into avoidance of tanning are probably in Southern Asia, or Asia in general. Their birth rates are not that low, with the exception of Japan, S. Korea and Taiwan.

[derefr]

The middle-class urban populations of these countries really liking lighter skin doesn't imply that the country as a whole will have light skin, though. Achieving that also requires that most of the country be middle-class and urban — being in the set of people who both have time to take care of their skin, and don't spend all day working outdoors in the sun in a way which will unavoidably result in tanning no matter how much sunscreen they use. This is true in Japan / South Korea / Taiwan; but not in these other countries, yet.

You can see it happening in China right now (which also culturally has a preference for lighter skin), as the last few decades of infrastructure build-up have led to a new generation whose parents are lower-class farmers but who are themselves middle-class white-collar workers. My hypothesis would predict a lower birth-rate among this cohort, while the previous generation's birth rate remains high.

[dekervin]

Here is the evolution of the share of blue collar/white collar jobs [0] vs the evolution of fertility rate [1]. I am curious to hear your conclusions from that !

[0] https://publishing.cdlib.org/ucpressebooks/view?docId=ft1580...

[1] https://www.researchgate.net/figure/Historical-Trend-in-US-T...

[bruce343434]

Isn't it a common phenomenon that smarter people have fewer children? Once you achieve high education people are more strategic about when, or if, to have children and how many.