Having worked in Russia for five years just after the collapse of the Soviet Union, I can attest to the quality of goods and services produced in a planned economy. There was little variety and terrible quality. Consumers had little ability to complain - they were either met with a shrug of the shoulders or just told to be happy they got anything at all.
In this great narrated presentation, Owen Barder argues that that the functioning of market economies is more akin to evolution than to design from above.
The key factors are variation and selection. He extends the analogy to international development, and makes several key points. First, we do have a profusion of development actors and initiatives, but not enough real variation; the strong pressure for aid coordination reduces experimentation. Second, we don't have good mechanisms for selection - failed or mediocre organizations and projects seem to plod along. And third, a critical factor for selection is the ability to get feedback directly from the intended beneficiaries.
I highly recommend setting aside a few minutes to watch this compelling and well illustrated video.