Trường tiểu học bắt đầu từ 9h thì tốt

nghiên cứu ở ấn độ,

và có lẽ ấn độ nên cần 2 múi giờ, mặt trời mọc ở đằng đông sớm hơn ở đằng tây tới 2 tiếng...

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After Independence (ngày độc lập), India adopted (nhận lấy) a single time zone (múi giờ duy nhất) for the entire country (quốc gia). India spans (nhịp) as much 1,822 miles in the East-West direction or 29 degrees longitude. If India followed the convention (quy ước) 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 (mặt trời có thể mọc sớm hơn hai giờ) 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 (làm giảm chất lượng giấc ngủ), especially of poor children and this reduces the quality of their education (làm giảm chất lượng giáo dục của họ). Why does a nominal change (thay đổi danh nghĩa) impact (ảnh hưởng) real variables (biến thực)? 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!

I find that later sunset causes school-age children to begin sleep later, but does not affect wake-up times. An hour (approximately two standard deviation) delay in sunset time reduces children’s sleep by 30 minutes. I also show that later sunset reduces students’ time spent on homework or studying, and time spent on formal and informal work by child laborers,while increasing time spent on indoor leisure for all children. This result is consistent with a model where sleep is productivity-enhancing and increases the marginal returns of study effort for students and work effort for child laborers.

The second part of the paper examines the consequent lifetime impacts of later sunset on stock indicators of children’s academic outcomes. I use nationally-representative data from the 2015 India Demographic and Health Survey (DHS) to estimate how children’s education outcomes co-vary with annual average sunset time across eastern and western locations within a district. I find that an hour (approximately two standard deviation)delay in annual average sunset time reduces years of education by 0.8 years, and children in geographic locations with later sunset are less likely to complete primary and middle school.