Speaking in numbers: The effect of reading performance on math performance among immigrants

- We estimate the causal effect of reading performance on math performance among immigrants.
- We combine PISA data with an innovative measure on language differences.
- Simple OLS regressions of reading on math performance are prone to ability bias.
- Exploit exogenous variation in reading performance due to differences in age-at-immigration across different linguistic distances.
- We find strong effects of reading performance on math performance.

This paper is the first to estimate a causal effect of immigrant students' reading performance on their math performance. To overcome endogeneity issues due to unobserved ability, we apply an IV approach exploiting variation in age-at-arrival and the linguistic distance between origin and destination country languages. Using four PISA waves, we find a strong influence of reading performance on math performance, highlighting the importance of early language support for immigrants for their educational career.