Which battle on the Russian front was a major turning point in world war II

The battle of Stalingrad. The battle in which an entire German army was encircled. In other words, they're screwed.

In a command economy, the matter of what goods to produce is handled by a central economic authority. Contrary to that, a free market is governed by individual choices. The production of goods can be handled either domestically, or it can be outsourced to foreign countries. Finally, making sure that the targeted customers are able to afford a service or a product is of the utmost importance.