„New findings from the Progress in International Reading Literacy Study (PIRLS) 2021 among fourth grade students show a clear correlation between reading performance and the number of books at home. On average, students from homes with more than 100 books score 64 scale points higher on the PIRLS reading achievement scale than students from homes with 10 books or fewer.“
EU-Kommission (Hrsg.), Education and Training Monitor 2023 (2023), S. 38f.
In Österreich betrug die Leistungsdifferenz 80 PIRLS-Punkte (Quelle: ibidem, Figure 20.)