"A critical period for language learning is often defined as a sharp decline in learning outcomes with age. This study examines the relevance of the critical period to English proficiency among immigrants in the US. It uses microdata from the 2000 US Census, a model of language acquisition from...

Linguistic distance, i.e. the dissimilarity between languages, is an important factor influencing international economic transactions such as migration or international trade flows by imposing hurdles for second language acquisition and increasing transaction costs. To measure these costs, we...