It’s not true that communism “works on paper” or “doesn’t work because people aren’t perfect”. It’s not the “perfect system” at all.
AS one poster said, it destroys prices. Without price information, no one knows the true costs of anything.
Suppose you and I both have companies that make tractors. My tractors are very inefficient and poorly made and cost $1,000. Yours are simple and cost $100. In the capitalist system, no one buys any of mine.
What’s even better is that the reason why mine costs so much is that it uses more steel, electronics, labor everything. These are “resources”. My tractor uses more “resources” so it costs more. Yours uses less. So society as a whole is benefited because less resources are used to solve a problem. Furthermore, price information present in the $100 tractors causes people to try to innovate. Maybe they can make a cheaper tractor. Prices of all inputs are readily observable to it is easy to optimize. Just get the most output with the cheapest inputs. Maybe a farmer seeing how much tractors cost will plant crops in such a way that eliminates the need for them. Planting will cost more but it will save money in the long run.
With a communist system, there are no prices, so no one knows how cheap or dear a given product is. No one has any information as to whether certain innovations would work better and be cheaper, as there are no prices of anything. It’s a ridiculous system as it doesn’t allow for any innovation or improvment or optimization of anything. It works well on paper if you think in terms of “cars”, “steel”, “ironing boards” and say make as many as you can and we’ll divy it up. But the capitalist system actually improves things.
Cars that cost slightly more but get better gas mileage and are more durable. Steel which varies in quality…cheap steel for building, more expensive for cars and such.
I’ll give you an example. A company called Nucor uses a process to melt scrap steel and use it for buildings, roads, etc. They’ve improved the process so it can be used for a wider variety of goods too.
Now to know that it was profitable to do this, Nucor had to know the price of
a) labor
b) scrap steel
c) electric furnaces (to melt scrap)
c) electricity (to power furnaces)
d) land (on which to build the plant)
e) building steel (which was previously made in cast iron furnaces)
f) shipping costs
They put all these things together and figured they could make a profit. The price of steel for many applications FELL. This means less inputs went into it even though Nucor still made a profit. Repeat this example millions of times in all aspects of the economy and you have the reason why the US is the most productive country.