As a general rule, Solomon is attributed with writing the entire book of proverbs. Any other name given is written of as a “pen name” of Solomon, I think out of a fear of what it would mean for “God-inspiration” if someone other than Solomon wrote the book. I see no other reason for not allowing the possibility that there were multiple authors of the proverbs, as we read them. There are places within the text that suggest Solomon is not the only author.

Author #1 – Solomon (Prov. 1:1)
Author #2 – “Wise Ones” (Prov. 24:23)
Author #3 – Agur, Son of Jakeh (Prov. 30:1)
Author #4 – King Lemuel (Prov. 31:1)
Author #5 – Amenomope, son of Kanakht (Prov. 22-23)

Attributing sayings Solomon wrote as being from “wise ones” does not detract from Solomon’s decision to record them. After all, “there is nothing new under the sun;” therefore, it would be foolish to suggest that there was no wisdom at all on the earth before the reign of Solomon. As for Agur, if this is a pen name for Solomon, what on earth is the point of “son of Jakeh?” I get that “agur” means collector, and yes, that certainly can apply to Solomon, but you have to deliberately ignore the heritage tag, which was extremely important to Jews, by the way, in order to lay that name on Solomon. A very interesting study I found was a comparison between The Instruction of Anememope from an Egyptian sage, which pre-dates the reign of Solomon, and Proverbs 22 and 23.

We know from the book of Ecclesiastes that, despite being given wisdom from God, Solomon went out into the world to soak up as much experience as possible while he searched for the meaning of life. I find it highly likely that, during his search, he read the great texts of his time period — one of those being The Instruction of Amenemope. Therefore, I believe it is probably more likely that Solomon both wrote–and assembled–the collection of proverbs from various places, not just from within himself. That being the case, the various “authors dilemma” is solved in positing Solomon is merely giving credit to the people from whom he heard certain of the proverbs which he decided, through God-inspiration, to record.

Tricia Reno