Research

The goal of this study is to identify the causal effect of 3G mobile network coverage expansion on fertility outcomes among households in Nigeria. We address the challenge of endogeneity by using an instrumental variable approach that instruments 3G mobile network coverage by lightning strikes densities, proposed by Guriev et al. (2021) and Manacorda & Tesei (2020). We find that access to 3G mobile networks assisted women in making informed decisions, reflected in reduced both fertility outcomes and intentions. While there is no observed effect on the overall number of children, 3G coverage increased the propensity of male children residing at home, indicating better care environment.

This paper presents a novel multi-treatment field experiment that investigates the spillover effects of targeted supplementary computer-assisted learning (CAL) and traditional paper-pencil workbook education interventions among 130 boarding schools in rural China. We also discuss the possible channels by which programs may have spillover effects on non-targeted peers' academic outcomes. We find that the paper-pencil workbook program has a negative spillover effect on untargeted non-boarding students’ school performance, but no spillover effect is detected in the CAL group. Our network interference results suggest that the negative spillover effects of the workbook program most strongly affect non-boarding students who have close-boarding peers in the same classroom. 

This paper aims to control for the endogeneity of peer group selection and identify causal relationships between peer effects and academic performance inside classroom microenvironments. Estimates based on instrumental variable approach indicate that study groups enhance student achievement by 0.11 standard deviations, and lower-ranked students benefit more from this effect. Self-concept and intrinsic motivation are channels behind these effects. Study groups, however, have no substantial effect on the learning outcomes or behavior of high-achieving students.  Additionally, peer effects are more pronounced in study groups characterized by greater cohesiveness or among male students.

This paper provides some of the first experimental evidence of the applicability of text messaging technology to improve parenting knowledge, promote stimulating parenting practices, and raise child development outcomes at ages 0-3 in low-income, under-resourced communities. We replicated and expanded a text messaging-based parenting intervention (Tips-by-Text) that has been shown to be effective in the U.S. but has not been tested in low- and middle-income countries (LMICs), where misconceptions about parenting are common and awareness of the importance of stimulating parenting practices is low. Overall, our results show substantial, positive impacts of Tips-by-Text on parenting knowledge (ITT = 0.222 SD, p < 0.01) and some important stimulating parenting practices (including maternal time investment in play activities; counting, drawing, and naming things with the child; and reading or looking at picture books with the child). While the average treatment effects on other parenting practices and on early childhood development outcomes are statistically insignificant in the sample overall, we found large heterogeneities in the treatment effects that were consistent with three behavioral economics concepts: lack of information, inattention, and motivated cognition. 

Early child development is important to human capital accumulation. Current studies find a positive effect of maternal migration on their early children development due to income increase and parenting knowledge improvements after migration. However, most of those studies lack detailed information on parental migration history. This is first ever study recording maternal monthly migration status. We conducted a survey of 781 households with children aged 1-23 months in rural China and constructed a dose-response estimates using a “generalized propensity score.” This paper uses propensity score matching to identify causal effects of parental migration on early childhood development. Results suggest a statistically significant positive effect of maternal migration on children development outcomes and mental health levels who migrates with them. However, there is no statistically significant effect of maternal migration on left-behind child.