Where there is public transport, it may not always operate in a regular or reliable fashion. Disadvantaged students may also have more responsibilities than advantaged students, such as the need to look after younger siblings and other family members and to undertake paid work before or after school. However, these improvements were largely among advantaged rather than disadvantaged students (OECD, 2016b). Argentina, Kazakhstan and Malaysia were not included in this figure, as coverage is too small to ensure comparability (see Annex A4 of OECD, 2016a).