[2] As a statistician, Koren's interests lay in social welfare and the description of societal problems, e.g. prison inhabitants,[3] crimes,[4] and alcoholism.
[5] Koren served as president of the American Statistical Association in 1913–14.
[6] To commemorate the 75th anniversary of this association in 1914, he edited a book about the history of official statistics in various countries.
The volume was delayed due to World War I and was finally published in 1918.
[8] He committed suicide by jumping overboard the Holland-America liner Nieuw Amsterdam.