"Earlier work (Oster, 2005) has argued, based on existing medical literature and analysis of cross country data and vaccination programs, that parents who are carriers of hepatitis B have a higher offspring sex ratio (more boys) than non-carrier parents. Further, since a number of Asian...

"Ichino and Moretti (2009) find that menstruation may contribute to gender gaps in absenteeism and earnings, based on evidence that absences of young female Italian bank employees follow a 28-day cycle. We analyze absenteeism of teachers and find no evidence of increased female absenteeism on a...