Sources; Incomes for workers are from Masumi Tsuda, Nihon no toshi kaso shakai [Urban lower-class society in Japan ] (Kyoto: Minerubu-shobo, 1972); original source is Saimin chosa tokeihyo tekiyo [Extracts from the poor people's survey statistics] (Tokyo: Ministry of Interior, 1912) (the investigation was carried out in 1912). Income for officials are given in Tokyo-fu takeisho [statistics of Tokyo Prefecture] (1909).