The EPI measures the number of jobs that would be lost from increased competition from Korean firms and subtracts the number to be gained through greater access to Korean markets. They get some nasty numbers – a net 159,000 jobs lost, as compared to no change in an estimate by the U.S. International Trade Commission (an establishmentarian, if not exactly anti-labor, source).

This difference hardly comes as a shock. Such calculations are more art than science. And for many years, centrist Democrats and many conservatives have succumbed to the temptation of defending open trade in terms of job creation. Think of NAFTA, and the wild enthusiasm of the Clintonites versus the giant-sucking-sound scenarios of protectionists.

But as economists, we’ve always found this debate a misunderstanding at best, and flat-out sophistry at worst. Almost everybody who bothered to stay awake in Econ 101 knows that, in the medium to long term, the total number of jobs is largely determined by macroeconomic factors – a mix of fiscal and monetary policy leavened by imponderables like savings rates. Trade is worthwhile because it increases total income indirectly by increasing the efficiency of production (classic “static” gains from trade) and, more importantly, by encouraging innovation through greater competition. There can be exceptions; indeed, a zillion PhD candidates have made their bones by dreaming up new ones. But, in the end, it’s a big stretch to make a broad case for messing around with using trade policy as a means of increasing jobs.

What trade undeniably does, though, is to create jobs for some and destroy jobs for others. Take the standard example of competition from the Japanese auto industry, which has surely led to better, cheaper cars. That makes most of us winners. But not the United Auto Workers and their families (or the city of Detroit), who would have been be better off if American trade policy had been used to strangle Toyota, Honda and Nissan in their cribs. The hope – and not a very realistic one – is that the losers will quickly and painlessly find attractive niches in the new order of things.

So what’s our point? Arguments about regulatory policy are almost always cast in terms of efficiency, but nobody except policy wonks really buys them. That’s one reason the White House made a modest effort to pass off the accord as good for American workers, when apparently the real reason was to come to the aid of embattled political allies in Korea – and maybe even to earn a few points with the free market wonks.

Nothing so dramatic happened in the wake of the 2008 financial meltdown. So, we must have learned our lesson with respect to trade, right? Yes and no.

Yes, the protectionist response this time around was weak tea compared to 1930. But there is no question that barriers to trade (mostly non-tariff barriers) were raised significantly in response to lobbying by protectionist lobbies in virtually all the world’s trade powers. Equally troubling, there has been little success in reversing the trend even though the global economy has plainly begun to recover. Indeed, judging by the record of the second half of 2009, the inertia driving protectionism remains quite formidable.

How do we know all this? We follow the Global Trade Alert (GTA) reports issued by the Center for Economic and Policy Research, the London-based think tank, and edited by Simon Evenett of the University of St. Gallen in Switzerland. The third GTA report, issued in December, offers a country-by-country compilation of protectionist initiatives along with assessments of the consequences for trade policy in some key economies (Russia, China, Japan, India). Read it and weep.