タイラー・コーエンとノアピニオン氏が自由貿易についてブルームバーグで論戦を交わしている(H/T Marginal Revolution*1)。以下はそこからの引用。

Cowen: ...why has Latin America turned from a region of autocrats to having plenty of vigorous democracies? It is very likely that participation in a broader global economic order has played a key role. ...
Smith: I agree about the overall benefits of trade. In China, particularly, there’s a very stark difference -- it went from very little foreign trade to a whole lot, and it's become much more prosperous. Everyone agrees trade was essential to its economic miracle. And likewise, if the U.S. were to shut itself off to trade, it would be a total economic disaster.
But economists are trained to think not in terms of overall benefits, but marginal benefits. The question is whether a little bit less free trade might have been better. And it’s here that I think economists have done too much one-way cheerleading and not enough thoughtful discussion of the costs versus the benefits. ...
Cowen: It’s not always so easy to choose a “little less” free trade. Take the integration of China into the global economic order. That was achieved in part by China’s entry into the WTO, which showed the Chinese leadership that world markets would indeed stay open if China liberalized and tried to compete. It worked. But that’s not a process the U.S. government can or should control, rather it was governed by a treaty. We need such treaties precisely because so many governments have their reasons for wanting a “little less” free trade, and then the final result is a lot less free trade.
Even without a treaty constraint, do you trust the American system of government to serve up the right marginal adjustments to free trade? I don’t. This is the same government that makes protection for farmers and intellectual-property holders a priority in its trade negotiations.
So when it comes to trade, again I say full steam ahead. Sometimes there may be overshooting from a domestic point of view, but the alternative is a lot of reasons never to move away from excess protectionism.
Smith: I’m advocating for more-nuanced and realistic rhetoric from economists. I say they shouldn’t just talk about the potential benefits of free trade, but also the potential costs. It seems like you’re saying that if economists are honest and nuanced, the result will be a hopeless mishmash of government pork, inefficient regulations and instinctive protectionism -- but that if economists simplify their message and present only one side of reality, government will end up doing mostly OK. ...
Cowen: I think we economists should tell the truth, not present overly simplified statements. And in my view the truth is that free trade has been overall better than what we economists had thought. We hadn’t understood or emphasized its dynamic international properties as we should have. And WTO entry has turned out to be very good for China, though at the time many observers wondered whether the country really could stick to the regime. That’s the true and nuanced view, and the benefits many economists missed turned out to be more important than the costs that were missed. ...
Smith: Let’s talk about these “dynamic international properties.” When you talk about Latin America, you imply that trade produces good government. Why haven’t we seen that in China, which has arguably benefited the most from trade agreements? The country seems to have become steadily more repressive since it joined the WTO in 2001. In fact, according to the think tank Freedom House, freedom in the world has been on the decline for 10 years. Why isn’t trade working its supposed magic here? In any case, with these big overall trends, it’s difficult to separate correlation and causation. ...
Cowen: Most of the decline in freedom in China has come in the last few years, when economic growth and foreign trade rates also have been falling. You mention that freedom in the world is down in the last 10 years, but note world trade takes a steep dip almost 10 years ago. I’m not suggesting we understand the cause and effect story here, but the overall pattern fits the standard neoliberal intuition, namely that international trade and freedom go together. That’s been the general connection for most of the past few centuries. ...
Smith: It would be odd if continuous increases in free trade are necessary to maintain levels of democracy. If that’s true, then free trade eventually hits a ceiling and democracy starts to backslide. If the governmental benefit from free trade is that ephemeral, it should probably be a minor long-term factor in our cost-benefit analysis. ...

・・・なぜ中南米独裁国家の地域から、活発な民主主義国の多い地域に変貌したのでしょうか? 広範な世界の経済秩序に参加したことが重要な役割を果たした可能性が非常に高いです。・・・
条約の制約が無かったとしても、米国政府は自由貿易の限界的な調整を正しく実行する、と思われますか? 私はそうは思いません。農家と知的財産保有者の保護を貿易交渉の優先事項にするような政府なのですよ。
その「動的な国際的特性」についてですが、貴兄は中南米に言及された時、貿易が良い政府を生み出すというようなことを言われました。なぜ貿易協定から最も利益を得たであろう中国でそれが起きなかったのでしょうか? 2001年のWTO加盟以降、同国は抑圧体制を絶えず強化してきたように見えます。実際、シンクタンクフリーダム・ハウスによると、世界の自由度は過去10年低下し続けています。貿易が持っているはずの魔法がなぜここでは効かないのでしょうか? いずれにせよ、こうした全般的な大きな傾向については、相関関係と因果関係を分離するのは困難です。・・・

*1:両者の論戦はシリーズ化しているようである。cf. ここで一端を紹介した前々回の討論、前回の討論