While Politicians yammer, enterprise does work
While the politicians run around the country telling us of their plans to make our lives better--what wizardry they command, merely to make speeches, pass laws, and print paper and thereby make us prosperous and secure!--free enterprise is busy actually accomplishing this, and with little or no fanfare.
In a world of scarcity, every choice requires that something else of value must be given up, and the highest-valued alternative given up is the opportunity cost.
That opportunity-cost emphasis focuses on the question of what is actually being given up when a choice is made.