William J. Bernstein in The Birth of Plenty:

Markets work best when all of the buyers and sellers of a particular item are confined to the same place at the same time. In such a situation, the pricing of that item becomes very "efficient", that is to say, everyone buys and sells at nearly the same price. (p. 43)

This is quite similar to the original brainstorming technique developed by Alex F.Osborn. He envisioned that during a brainstorming session people wouldn't go into analysis or problem solving right away. Rather, they would try to come up with as many ideas as possible in a judgment-free environment. Only later, when a good number of potential solutions is collected [or the time runs out], the same or a completely different group of people would do an evaluation session. As the result of the whole exercise, brainstormers would create a market for ideas and solutions.

Over time, the original brainstorming evolved into problem-solving meetings, and the free-wheeling idea market approach got lost along the way. Too many ideas, too little time.