Calculating the costs of shutting borders to trade

Across North America and Europe, lockdowns of entire communities and countries are underway. Borders are closing to travel even as governments insist that cargo and trade will still be allowed to pass. That may be a moot point. Economies running into a brick wall tend to see collapses in trade. We learned that in 2009.

The evidence so far this year from Asian economies like China, Japan and South Korea that were hit earlier than western ones is that the coronavirus crisis and the resulting shutting down of industry will have a severe impact on trade no matter what the politicians say.

But what if governments took the next step and decided to halt trade altogether as part of their efforts to slow the spread the Covid-19 virus? What would be the economic impact then?

In a conversation with the Dartmouth College economic historian Douglas Irwin last week, he remembered that work by economists had been done on exactly that. Because there’s an example in U.S. economic history Irwin has spent some time looking at it as well. (Irwin followed our conversation up with a thread on Twitter over the weekend.)At the request of the U.S. Treasury and the Department of Homeland Security, a group of economists at Australia’s Monash University in 2012 modeled what the economic impact would be of a total shutdown of the U.S. border to cargo and people in the event of a public health threat like a pandemic.They considered various scenarios, the most extreme of which called for the trade in 95% of goods to be suspended for 12 months. The impact on the U.S. economy? A fall in real gross domestic product of 48%.

There are, of course, fans of greater trade restrictions who would dispute that finding. There is also an example in American history — albeit one long before the days of global supply chains — to draw on that points to a milder though significant impact.In December 1807 the U.S. Congress at President Thomas Jefferson’s urging imposed an embargo on trade to protest British and French naval harassment that lasted until March 1809.

In a 2005 paper, Irwin calculated that the embargo cost the U.S. 5% of its gross national product at the time. But it also became as close to a natural experiment in autarky as the U.S. has ever experienced in peacetime.

As Irwin lays out, the value of U.S. goods exports fell from from $49 million in 1807 to $9 million in 1808. Meanwhile, the value of imports fell from $85 million in 1807 to $45 million in 1808 — a decline of nearly 50 percent.We’re not there yet. Except for international travel, the shutdown underway in the U.S. and European economies now is largely domestic. Any effect on trade we are likely to see is a secondary effect of economies closing down temporarily rather than the borders being closed to cargo.

That doesn’t mean, though, that in an age of rising protectionism and populist economic nationalism with a pandemic rattling the world the economic costs couldn’t soar even further.