Communism failed for one simple reason: it was rational. Communism was about a planned economy, about figuring oiut what people's wants and needs are by mathematics. The only problem was that people's wants and needs can not be simplied to basic numbers, based on historical treneds, but on what the psyche desires and craves, and other factors of nature such as a weather or media event. All of these things could be catagorized as irrational factors. Let's consider several dimensions of irrationality.

Media Events. Media can have a profound effect on the psyche. We see something on a commerical and see that our lives could be better for us. So we want to buy it. Communism might be able to predict a positive reaction to an ad campaign, but it would be difficult to figure out how many people would be repulsed and not buy the product. That's a matter of the individual's own experience.

Experience. Experience will define where a person is in a particular moment of time, and will define how a person acts a specfic time. The only problem is that nobody truly knows an another's individual's experience as no two people can share the exact same vantage point. While we can predict some aspects of experience, many will always remain foreign.

Nature. We understand many things about our environment, but we also don't understand many other aspects. Communism like capitalism at times, believed that all of nature could be cntrolled, and that it existed only for own benifit. Such thinking was limited, and ultimately created environmental discression.

Economy. People are inheritably irrational when it comes to buying things. People want products not only out of raw need, but also desire. Things often break unexpectly, or disasters happen, that makea product to be in need. Capitalism deals effectively by these irrational needs and wants, by raising prices in comparision to demand.

Any system that tries to view problems in truly rational terms is bound to fail. Human kind is not made up of numbers, but instead of individuals who make choices based on complex experiences that we will never be able to predict. Ultimately the best system will respect irrational demands, and find ways to insure that a diverse population can flourish.