Lamote de Grignon Pérez et. al. 2025: "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 more than twice as many work hours as standard questionnaires. This discrepancy suggests that current estimates may significantly understate child labour. Moreover, certain forms of work—such as collecting water or firewood—appear to contribute to these measurement gaps.