The time of Abraham

[Wikipedia](https://en.wikipedia.org/wiki/Abraham) says that the story of Abraham is fictional, an ex-post construction: > The Abraham story cannot be definitively related to any specific time, > and it is widely agreed that the patriarchal age, along with the > exodus and the period of the judges, is a late literary construct that > does not relate to any period in actual history. A common > hypothesis among scholars is that it was composed in the early Persian > period (late 6th century BCE) as a result of tensions between Jewish > landowners who had stayed in Judah during the Babylonian captivity and > traced their right to the land through their "father Abraham" but I recently read that Abraham time is about 1980 B.C. Does anyone happen to know how this speculation was derived and what currency it has?