Jeremiah 49:14-16 and Obadiah vv. 1-4 -- who came first?

Question

Among the oracles against Edom in the Hebrew Bible, there is one that is shared between Jeremiah and Obadiah: Jeremiah 49:14-16 and Obadiah vv. 1-4. Although the "table" is a bit wide for this format, it helps to set these passages out in parallel columns (NASB cited):

+--------------------------------------------------+--------------------------------------------------+
|                 Jeremiah 49                      |                  Obadiah                         |
+--------------------------------------------------+--------------------------------------------------+
| -                                                | 1 The vision of Obadiah.                         |
| 7 Concerning Edom.                               | Thus says the Lord GOD concerning Edom—          |
| Thus says the LORD of hosts,                     | \                                                |
| . . .                                            | \                                                |
| 14 I have heard a message from the LORD,         | We have heard a report from the LORD,            |
| And an envoy is sent among the nations,...       | And an envoy has been sent among the nations..., |
| “Gather yourselves together and come             | “Arise and let us go                             |
| against her, And rise up for battle!”            | against her for battle”—                         |
| 15 “For behold, I have made you small            | 2 “Behold, I will make you small                 |
| among the nations,                               | among the nations;                               |
| Despised among men.                              | You are greatly despised.                        |
| 16 “As for the terror of you,                    | \                                                |
| The arrogance of your heart has deceived you,    | 3 “The arrogance of your heart has deceived you, |
| O you who live in the clefts of the rock,        | You who live in the clefts of the rock,          |
| Who occupy the height of the hill.               | In the loftiness of your dwelling place,         |
| \                                                | Who say in your heart,                           |
| \                                                | ‘Who will bring me down to earth?’               |
| Though you make your nest as high as an eagle’s, | 4 “Though you build high like the eagle,         |
| \                                                | Though you set your nest among the stars,        |
| I will bring you down from there,”               | From there I will bring you down,”               |
| declares the LORD.                               | declares the LORD.                               |
+--------------------------------------------------+--------------------------------------------------+

^{Backslash \ indicates continuous text in the column; ellipsis ... = omitted text.}

It seems fair to assume that Jeremiah is borrowing from Obadiah, or Obadiah from Jeremiah.

• The main question, then: Is that, in fact, a fair assumption? what other scenarios could explain this "doublet"?
• As a secondary concern: If one is borrowing from the other, by what criteria does one decide which direction the dependency runs?

There are other such cases (e.g., Isaiah 2:1-4 // Micah 4:1-4); one hopes that the criteria which apply in one case could be sufficiently generalized (or generalizable) to apply in these other cases as well.

Answer 1

Scholarly consensus is that both the Jeremiah and Obadiah oracles you mention are drawn from an anonymous source earlier than either, rather than that either one is "plagiarizing" directly from the other. This scenario would be similar to the hypothesis of the Q source as the common origin for similar sayings by Jesus in Matthew and Luke.

See, for example, S. David Sperling in Encyclopedia Judaica:

However, it should be noted that there is a clear similarity between Jeremiah 49:7–22 and Obadiah 1–11 (cf. Obad. 1–4, 5–6, 8 with Jer. 49: 14–16, 9–10a, 7). A careful comparison of the two recensions seems to indicate that the common elements have been derived from an older source. It may therefore be inferred that in his oracle on Edom the author of Jeremiah 49:7–22 incorporated passages from an anonymous source, which was still later included in the Book of Obadiah.