In recent years, ethnic residential concentration and negative consequences in ethnic minority neighborhoods have increased. This volume presents scientific knowledge and contributes to the societal debate by studying the effects of ethnic residential concentration on ethnic minoritiesAE social contacts and language practices. The study indicates that ethnic residential concentration is related to less social contact with natives, but more social contact with co-ethnics. As a result, ethnic residential concentration hinders ethnic minoritiesAE majority language proficiency and use. Moreover, ethnic residential concentration is found to constrain the strength of ethnic minoritiesAE social ties with natives, and the rise of ethnic concentration partly explained the stagnation of ethnic minoritiesAE social contacts with natives over time. Implications of these results are discussed. | In recent years, ethnic residential concentration and negative consequences in ethnic minority neighborhoods have increased. This volume presents scientific knowledge and contributes to the societal debate by studying the effects of ethnic residential concentration on ethnic minoritiesAE social contacts and language practices. The study indicates that ethnic residential concentration is related to less social contact with natives, but more social contact with co-ethnics. As a result, ethnic residential concentration hinders ethnic minoritiesAE majority language proficiency and use. Moreover, ethnic residential concentration is found to constrain the strength of ethnic minoritiesAE social ties with natives, and the rise of ethnic concentration partly explained the stagnation of ethnic minoritiesAE social contacts with natives over time. Implications of these results are discussed.