“…The general pattern in these studies is that the students who have better sleep habits do in fact receive higher grades, but these papers generally only measure simple correlations. 8 More broadly, research on school starting times is related to recent research by economists on the structure of the school day (Eren and Millimet 2007) and the amount of time spent in school (Eren and Millimet 2007;Krashinsky 2006;Marcotte 2007;Marcotte and Hemelt 2008;Hansen 2008;Pischke 2007). Even more broadly, economists studying time use have expanded their analysis beyond the simple hours tradeoff between labor and leisure to include sleep (Biddle and Hamermesh 1990;Brochu, Deri Armstrong, and Morin 2009), other activities (Aguiar and Hurst 2007;Guryan, Hearst, and Kearney 2008;Krueger 2007), and timing of activities throughout the day (Hamermesh 1998(Hamermesh , 1999a(Hamermesh , 1999b(Hamermesh , 2002Hamermesh, Myers, and Pocock 2008 The ACT data is student-level data on all students in grades 10-12 in public schools from the 48 districts (73 schools 2010).…”