Estimating how much children work: Questionnaires versus time use diaries

Current estimates of child labour often rely on questions such as, “How many hours did you work last week?” While biases in adult self-reports are well documented in high-income countries, there is limited evidence on the accuracy of children’s responses in low- and middle-income countries (LMICs). Using data from nine LMICs, including China and India, this paper shows that time diaries report considerably more work hours than standard questionnaires. The gap is particularly large among younger children, with ratios of diary to questionnaire estimates exceeding five at ages 5–11 and remaining above two even among adolescents aged 15–17. This suggests that current estimates may substantially understate child labour. Moreover, certain forms of work—such as collecting water or firewood—appear to contribute to these measurement gaps. • This paper shows that stylized questionnaires substantially understate children’s work relative to time-use diaries. • Across nine low- and middle-income countries including India and China, diary-based estimates of child work hours are on average 2.6 times higher. • Under-reporting is most severe among younger children and for less salient activities such as water collection, fuel collection, and work-related travel. • The results imply that widely used questionnaire-based measures introduce non-classical measurement error into child labour statistics and related empirical work.