“…The second strand of literature, to which our study is more closely related, is the effect of peer group composition in the class or grade on educational achievement and behaviour (Bui, 2014;Carrell and Hoekstra, 2010;Gaviria and Raphael, 2001;Hill, 2017;Hoxby, 2000;Lavy et al, 2012a;Lavy and Schlosser, 2011;Mora and Oreopoulos, 2011). Most existing studies find evidence that peer gender effects significantly effect educational achievement, major choice, graduation rates and engagement in risky behaviour, with the effects on male students being a little larger (Fischer, 2017;Hill, 2017;Horoi and Ost, 2015;Hoxby, 2000;Lavy and Schlosser, 2011;Sacerdote, 2011).…”