Access to books helps close the literacy gap in kindergarten
Fryer and Levitt (2004) examined reading and math test scores in kindergarten and grade 1 from the Early Childhood Longitudinal Study (about 1000 schools). Their focus was the gap between black and white children.
For reading, the difference between black and white children at the start of kindergarten was .40 (where 0 = mean, sd = 1). Thus, black children scored 40% of a standard deviation below white children.
When Fryer and Levitt controlled for SES, (parents occupation, parent occupation, household income), the gap dropped to .134.
When they controlled for SES and number of children's books in the home the gap dropped to nearly zero, -.006.
This is a major result: the presence of children's books evens the playing field. And this is only for a test given at the start of kindergarten. Sadly, this report was buried deep in the paper: "Including number of books …. completely eliminates the gap in reading" (p. 452).
This result is consistent with studies that show that supplying even a modest number of books for read alouds to parents of young children of poverty helps close the vocabulary gap between children of poverty and national norms. (For a review of "Reach out and Read" studies, see Krashen, 2011). The finding is also consistent with studies done with older readers showing that access to a library can ameliorate the effect of poverty on reading achievement (Krashen, Lee and McQuillan, 2012).
When Fryer and Levitt controlled for more predictors, including age the child was when in kindergarten, birth weight, if the mother was a teenage mother at first birth, if the mother was 30 or older at first birth, the characteristics of neighborhood, whether the mother worked, preschool program participation, parental involvement in child's life, family size and structure, the difference was .093: Black children did slightly better.
Fryer, R. and Levitt, S. 2004. Understanding the black-white test score gap in the first two years of school. The Review of Economics and Statistics 86 (2): 447-464.
Krashen, S. 2011. Reach out and read (aloud). Language Magazine 10 (12): 17-19. (languagemagazine.com/?page_id=2688)
Krashen, S., Lee, S.Y. and McQuillan, J. 2012. Is the library important? Multivariate studies at the national and international level. Journal of Language and Literacy Education, 8(1): 26-36. (http://sdkrashen.com/articles.php?cat=2)