A new ebook from Vox--The great trade collapse: what caused it and what does it mean?--is the latest in a very impressive series of rapidly compiled symposiums on current economic issues. The introduction by editor Richard Baldwin gives an excellent, concise overview. I especially recommend Simon Evenett's chapter on crisis-era protectionism, which corrects the view that governments have by and large learned the lessons of the Great Depression, and have avoided damaging trade-policy responses to the slump. Things have been quiet so far as tariffs are concerned, but there are more way to export your unemployment than raising tariffs.

- Since taking their pledge to eschew protectionism, G20 governments have together implemented 179 measures that harm foreign trade, investments, workers, and intellectual property.

- On average, every other day a G20 government has broken the pledge [to eschew protectionism for a year] made in Washington DC last November.

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