Also, when you have fixed pricing on products, there's suddenly no reliable feedback on what people really need. Now you can gauge it from how much they are ready to pay for a product, but with fixed pricing that is lost. And then the factories are constantly producing too much of something or too little of it.

And especially when it constantly happens that there is too little of this and that, a black market is practically sure to appear to get people what they need. And that grows corruption that then destroys the rest. Hooray.

Of course you can just ask people if they would want to have __________. But often they answer "yes" to things they won't bother to get anyway or "no" to things they will actually end up liking once their friends notice how nice they are. So, in reality that doesn't really help. You can also build some very advanced computer system that follows everyone in realtime and always guesses with a high precision what the people need at each time. But then we have a very horrible system where we are being spied on every moment. Not what I want, either.

If this problem doesn't get tackled, socialism cannot work.