It's very difficult indeed for us to map out exactly how it would all turn out if the government really were to run the economy in detail. Thus we need to try and find a comparator, somewhere that has two economic systems and we can observe the different outcomes.
We can of course think of the grand experiment that was the 20th century. Those places that had state socialism ran a race against those that used markets and the state socialism lost. But of course no one calls for such any more - at least we are continually assured.
But there are people calling for a democratic economy - that is, one where everything is decided through voting on committees. Others call for the bureaucratic economy, where the committees decide and there're even those absurdists who demand a Courageous State, where politicians decide each detail.
What we would like to find therefore is somewhere which has something like our market mix and right next to it something more like that state run and controlled economy so we can observe the different outcomes. Fortunately we have this - the United States. Government, planning, bureaucratic control, once again lose:
Imagine if the government were responsible for looking after your best interests. All of your assets must be managed by bureaucrats on your behalf. A special bureau is even set up to oversee your affairs. Every important decision you make requires approval, and every approval comes with a mountain of regulations.
How well would this work? Just ask Native Americans.
The federal government is responsible for managing Indian affairs for the benefit of all Indians. But by all accounts the government has failed to live up to this responsibility. As a result, Native American reservations are among the poorest communities in the United States.
Hmm, perhaps government isn't the way to run life and the economy then?