“…2 The importance of instructional time for student achievement varies between educational systems, and in particular, between developed and developing countries (Woessmann, 2016), pointing towards potentially important complementarities in educational production, for example, between instructional time and teacher quality or effective classroom management techniques (Rivkin and Schiman, 2015). 1 labour market outcomes, to have positive physical and mental health benefits, and to raise subjective well-being over and beyond other benefits (Wilson and Musick, 2012), as confirmed in both observational (Binder and Freytag, 2013;Borgnonovi, 2008;Meier and Stutzer, 2008) and experimental studies Aknin et al, 2008). Specifically for youth, there is evidence that volunteering from an early age on enhances psychological development by raising self-esteem and self-confidence and by discouraging risky behaviours (Hart et al, 2007;Wilson and Musick, 2012).…”