About that self-sufficiency...............

     In a modern economy, no one is self-sufficient.  Instead, people are specialized.  The work you do probably does not produce something you could consume.  Even more striking is the fact that almost everything you consume is something you could not possibly produce.  Your daily life depends on the cooperation of hundreds of millions of other people...

We carry on our lives not really conscious of the complexity of that specialization.  In fact, when it enters our minds, we often resent it.  We praise ourselves for our urban gardens and our do-it-yourself home projects.  We urge on another to "buy local," and we berate business executives for moving jobs overseas.  Of course, if we took such sentiments to their logical conclusion and tried to eliminate commerce with strangers entirely, we would have to return to primitive hunting and gathering.

-Arnold Kling,  Specialization and Trade:  A Re-Introduction to Economics