Socially attractive hypothesis with empirical challenges

From Poor Sleep Makes People Poor: The Costs of India Standard Time by Alex Tabarrok.

After Independence, India adopted a single time zone for the entire country. India spans as much 1,822 miles in the East-West direction or 29 degrees longitude. If India followed the convention of a new time zone every 15 degrees it would have at least two time zones. With just one zone the sun can rise two hours earlier in the East than in the far West.

In an original and surprising paper, Maulik Jagnani, argues that India’s single time zone reduces the quality of sleep, especially of poor children and this reduces the quality of their education. Why does a nominal change impact real variables? The school day starts at more or less the same clock-hour everywhere in India but children go to bed later in places where the sun sets later. Thus, children in the west get less sleep than children in the east and this shows up in their education levels and later even in their wages!

The hypothesis that sleep deprivation causes poor academic performance is logical and there are a lot of advocates for that as a root cause of poor performance. Jagnani has an interesting and innovative experiment to exploit natural conditions (the fact that India is a single time zone. Kudos for creativity.

But are children sleep-deprived and does that sleep deprivation reduce their academic performance? There is a reasonable amount of pushback in the comments. Apparently China has only a single time zone even though they geographically cover five time zones. Is there a similar west-east sleep deprivation gradient with consequent academic issues?

I am sympathetic to the idea that there might be some sleep deprivation and that adjusted school starting times might be beneficial, especially to teenaged students. It all sounds so logical. And yet . . .

Are kids really that sleep deprived? I have seen plenty of evidence saying yes and plenty saying no. I suspect we are still in the stage of transitioning from lazy and ideological research to more rigorous and reliable research. We won't know for a while.

And why ideological? In the US studies, sooner or later, they reference sleep deprivation being the explanation for lower academic performance either by class or race. Some of the research sounds like they are stretching to find a reason for race and class differences they find objectionable. My suspicion is that in the social justice miasma of academic circles, there is a social reward mechanism for finding that student sleep deprivation is real and that that real sleep deprivation has material academic consequences on specific minorities and the lower quintiles. And parents from the top quintile of class but with a lower quintile student love having some exogenous cause.

I take the hypothesis as possible but not proven. Seems like most the commenters are in the same boat with plenty of confounds and counterfactuals raised.