Linguistic diversity, school language of instruction policy, and learning outcomes across Asia and the Pacific

Children appear to learn better when taught in their mother tongue. This finding gives rise to an argument that mother tongue-based multilingual education could effectively improve learning outcomes in low- and middle-income countries. However, the challenges of implementing an effective multilingual education could prove prohibitive in countries with a high language diversity. Before embarking on the process of introducing multilingual education, policymakers should consider whether a correlation between language diversity and learning outcomes exists, and also, whether a particular language of instruction policy, monolingual or multilingual, correlates with learning outcomes. We construct a data set on the language of instruction policy across Asia and the Pacific and combine it with international assessment results. We find no evidence that countries with a richer linguistic diversity, controlling for income level, have significantly different learning levels. We also find evidence that learning outcomes are higher in countries with a monolingual education policy after controlling for income level and language diversity. Our findings imply that policymakers must seriously consider the potential challenges and benefits of a multilingual education policy before implementing it.