I think the two go hand in hand....
I think economic planning tends is often be better under socialism, but overall has worse results as the government has a greater responsibility for failings (it's more obvious).
Take our current economic climate in the UK, is it a strong, stable, well planned economy? - I'd say it is not; rather I couldn't have imagined a realistic method for the Tories to drop the ball more than they have done. It just so happens that so much has been privatised that there is limited impact.
In my opinion the current system vaguely works as follows:
-> Tax collected from Financial services
-> Government makes dumb decision
-> Markets React
-> Foreign giants come in
-> Mix of public and private investment
-> Passes though the city paying for some bankers along the way
-> Project gets funded and the rest goes back into the indirection machine
-> Debt rises but is largely privately owned
-> Life goes on
If you don't believe me, look into what owns Heathrow, it's run by a Quasi-Spanish based conglomerate and the China Investment Corporation. Britain has just been going along for the ride in a globalist system, as such the government has lost all ability to make rational economic plans, but also doesn't even need to any-more.