Reading when the sun does not shine: The effect of reading on children’s academic performance

The study aims to determine if reading outside of school positively impacts children's academic performance, drawing on Scholarly Culture Theory (SCT). SCT posits that a strong reading culture at home fosters skills that enhance academic success. Unlike other aspects of cultural capital, reading is hypothesized to be a key driver of this association. The research specifically focuses on children's own reading for enjoyment, recognizing its role in developing cognitive and analytical skills.

Addressing inferential challenges like reverse causality (better performers read more) and omitted variable bias (unobserved characteristics influencing both reading and performance), the study employs a 'natural experiment' approach. It uses cross-time variations in sunshine exposure as an instrumental variable, arguing that less sunshine leads to more indoor reading time. This strategy, combined with a fixed-effects design, controls for confounding factors. The hypothesis includes that children from families with stronger scholarly cultures and higher socioeconomic status (SES) will respond more strongly to changes in sunshine by reading more.

The research uses time-diary data from the Panel Study of Income Dynamics – Child Development Supplement (PSID-CDS), linking it with county-level sunshine data. The dataset includes information on children's academic performance (reading and math test scores), family scholarly culture indicators (books and newspaper subscriptions), and SES. Instrumental Variable (IV) methods for panel data are used for analysis.

The study yields three main findings: 1) Children are less likely to read when exposed to more sunshine, validating sunshine as a relevant instrumental variable. 2) Reading has a positive effect on children's reading test scores but not on math test scores, suggesting domain-specific skill development. This effect is argued to represent long-term impacts, not just daily. 3) While heterogeneity in the effect of the instrument (sunshine) was explored, statistical power was insufficient to definitively detect differences between groups based on scholarly culture or SES, though some weak evidence suggested children from higher-income families might read more with less sun.

Robustness checks addressed concerns like the 'Matthew effect' (skilled readers reading more when less sun), confirming the instrument's exogeneity. The study concludes that children's reading outside of school positively impacts their reading academic performance, highlighting the importance of scholarly culture and offering a novel approach to identifying this causal link despite existing inferential challenges.