估计儿童工作时长：问卷与时间使用日记的比较

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.