Kash at Angry Bear, a left of center economist, writes eloquently on trade and economic integration:
I’m not sure why we care more about economic integration than other
types of economic change. Every time there is a technological
innovation, some people benefit but others lose. Every time a person
decides to patronize one store over another, some people benefit but
others lose. Every time any economic transaction happens, in fact,
there are winners and losers. Why does it make a crucial difference
whether or not that transaction happened to cross a national border?…
When thinking about the costs and benefits of economic integration, why
should we only consider those that apply to people in our own country?
Is there any particular reason that I should care more about the
welfare effects of economic integration on people in Lubbock, Santa
Barbara, or Chattanooga than the effects on people in Lucknow, Sao
Paolo, or Chongqing? Personally, I can’t think of any good reason why.
Me neither. I also like Kash on the market test.
I realize that some of you are disappointed that I agree with the
orthodoxy by thinking that international economic integration is
generally a good thing, despite the fact that I call myself "liberal".
And I realize that some of you think that economists are all simply
brain-washed when it comes to international trade. But…if the vast majority of economists agree
about something, it’s not because we are simply turning off our brains
(and analytical power) on that one subject. It’s because the theory and
evidence on the subject are convincing, and have withstood relentless
efforts to debunk it. In general most economists think economic
integration is a good thing, not because it’s convenient to do so, but
because the work of thousands of extremely smart people working over
decades has convinced us that it usually is.