Jewish tradition has considered the books of Ezra and Nehemiah a single work. Their separation was first attested in the third century a.d. by the church father, Origen. Recognition of the original unity of the books is important for interpretation, requiring us to look for the structure and meaning of the whole work.
It is generally agreed that there are several identifiable sources the author utilized in his composition. The largest are two separate first-person accounts, one by Ezra, the other by Nehemiah, usually considered their respective “memoirs.” The Ezra memoir comprises Ezr 7-10 and perhaps Ne 8-10. Nehemiah's memoir is found in Ne 1-7 and most of chs. 12 and 13. The first six chapters of Ezra are composed primarily of official documents, mostly in Aramaic (4:8-6:18), together with traditions reflected in the prophecies of Haggai and Zechariah. The remaining material is thought to have originated with the author.
In view of the extensive sources used in Ezra-Nehemiah, the designation “author” is somewhat misleading. It is probably more accurate to speak of the compiler or redactor who selectively used these sources together with other material to convey a particular message. We must also consider the possibility that there were several stages of redaction before the final work appeared.
The Talmud (Baba Bathra 15a) attributes authorship of both books, as well as Chronicles, to Ezra. This tradition has been supported by some modern scholars. The consensus in current scholarship, however, is that an unnamed Jew who lived in the fourth or third century b.c. was responsible for these books. The compiler is usually called the chronicler due to the conventions and themes these works share. Recently several interpreters have challenged this theory.