...There are really only two things that you have to know about economics.
As with, say, the two things about boxing: hit, don't get hit. In
economics these are 1) incentives matter and 2) opportunity costs. The
first of these we all intuitively grasp, the second sadly vast swathes
of the country do not. And the wish is that we get the education system
sufficiently sorted out so that every child does indeed understand this
vital idea.x
Tim Worstall, http://www.adamsmith.org/blog