I think Paul Krugman is wrong today on international trade. For we find him in “plague on both your houses” mode. On the one hand:

Paul Krugman: Trade and Tribulation and A Protectionist Moment?: “Protectionists almost always exaggerate the adverse effects of trade liberalization…

…Globalization is only one of several factors behind rising income inequality, and trade agreements are, in turn, only one factor in globalization. Trade deficits have been an important cause of the decline in U.S. manufacturing employment since 2000, but that decline began much earlier. And even our trade deficits are mainly a result of factors other than trade policy, like a strong dollar buoyed by global capital looking for a safe haven.

And yes, Mr. Sanders is demagoguing the issue…. If Sanders were to make it to the White House, he would find it very hard to do anything much about globalization…. The moment he looked into actually tearing up existing trade agreements the diplomatic, foreign-policy costs would be overwhelmingly obvious. In this, as in many other things, Sanders currently benefits from the luxury of irresponsibility….

But on the other hand:

That said… the elite case for ever-freer trade, the one that the public hears, is largely a scam…. [The] claims [are] that trade is an engine of job creation, that trade agreements will have big payoffs in terms of economic growth and that they are good for everyone. Yet… the models… used by real experts say… agreements that lead to more trade neither create nor destroy jobs… make countries more efficient and richer, but that the numbers aren’t huge….

False claims of inevitability, scare tactics (protectionism causes depressions!), vastly exaggerated claims for the benefits of trade liberalization and the costs of protection, hand-waving away the large distributional effects that are what standard models actually predict…. A back-of-the-envelope on the gains from hyperglobalization — only part of which can be attributed to policy — that is less than 5 percent of world GDP over a generation…. Furthermore, as Mark Kleiman sagely observes, the conventional case for trade liberalization relies on the assertion that the government could redistribute income to ensure that everyone wins—but we now have an ideology utterly opposed to such redistribution in full control of one party…. So the elite case for ever-freer trade is largely a scam, which voters probably sense even if they don’t know exactly what form it’s taking….

And, Paul summing up:

Why, then, did we ever pursue these agreements?… Foreign policy: Global trade agreements from the 1940s to the 1980s were used to bind democratic nations together during the Cold War, Nafta was used to reward and encourage Mexican reformers, and so on. And anyone ragging on about those past deals, like Mr. Trump or Mr. Sanders, should be asked what, exactly, he proposes doing now.… The most a progressive can responsibly call for, I’d argue, is a standstill on further deals, or at least a presumption that proposed deals are guilty unless proved innocent.

The hard question to deal with here is the Trans-Pacific Partnership…. I consider myself a soft opponent: It’s not the devil’s work, but I really wish President Obama hadn’t gone there…. Politicians should be honest and realistic about trade, rather than taking cheap shots. Striking poses is easy; figuring out what we can and should do is a lot harder. But you know, that’s a would-be president’s job…. [But] he case for more trade agreements—including TPP, which hasn’t happened yet—is very, very weak. And if a progressive makes it to the White House, she should devote no political capital whatsoever to such things.

So I guess it is time to say “I think Paul Krugman is wrong here!” and fly my neoliberal freak flag high…

On the analytics, the standard HOV models do indeed produce gains from trade by sorting production in countries to the industries in which they have comparative advantages. That leads to very large shifts in incomes toward those who owned the factors of production used intensively in the industries of comparative advantage: Big winners and big losers within a nation, with relatively small net gains.

But the map is not the territory. The model is not the reality. An older increasing-returns tradition sees productivity depend on the division of labor, the division of labor depends on the extent of the market, and free-trade greatly widens the market. Such factors can plausibly quadruple The Knick gains from trade over those from HOV models alone, and so create many more winners.

Moreover, looking around the world we see a world in which income differentials across high civilizations were twofold three centuries ago and are tenfold today. The biggest factor in global economics behind the some twentyfold or more explosion of Global North productivity over the past three centuries has been the failure of the rest of the globe to keep pace with the Global North. And what are the best ways to diffuse Global North technology to the rest of the world? Free trade: both to maximize economic contact and opportunities for learning and imitation, and to make possible the export-led growth and industrialization strategy that is the royal and indeed the only reliable road to anything like convergence.

So I figure that, all in all, not 5% but more like 30% of net global prosperity–and considerable reduction in cross-national inequality–is due to globalization. That is a very big number indeed. But, remember, even the 5% number cited by Krugman is a big deal: $4 trillion a year, and perhaps $130 trillion in present value.

As for the TPP, the real trade liberalization parts are small net goods. The economic question is whether the dispute-resolution and intellectual-property protection pieces are net goods. And on that issue I am agnostic leaning negative. The political question is: Since this is a Republican priority, why is Obama supporting it without requiring Republican support for a sensible Democratic priority as a quid pro quo?

That said, let me wholeheartedly endorse what Paul (and Mark) say here:

as Mark Kleiman sagely observes, the conventional case for trade liberalization relies on the assertion that the government could redistribute income to ensure that everyone wins—but we now have an ideology utterly opposed to such redistribution in full control of one party…. So the elite case for ever-freer trade is largely a scam, which voters probably sense even if they don’t know exactly what form it’s taking….