COMMENT | Donald Trump has overturned the cart with his illogical, hasty, and emotional imposition of tariffs across the board, leading to considerable uncertainty in markets, especially stock markets, which are tumbling.

That’s the way markets react. On good news, they rise too sharply, and on bad news, they go down too fast. If people think Armageddon is around the corner, fear not, the damage is almost always less dire than what the disaster portends.

It helps to look at things broadly. Remember, the tariffs affect one country’s trade against the rest of the world, not the trade of the rest of the world with each other. That does not change.

Yes, the US is a big exporter and importer, but how big will give us an indication of the impact on the world trade in goods. We exclude the trade in services because the so-called invisibles, such as insurance, freight, and other intangibles, are not affected by the tariffs.

Best estimates put the total value of trade at around US$50 trillion, including exports and imports per year.

Which is the world’s largest...