Firing line,

proportion of their foreign exchange reserves, Mr. Shearing points the finger at the likes of Turkey ( 96.1%), Indonesia (95.7%) and South Africa (93%), with Mexico only the seventh most vulnerable major emerging market country by this measure, as the second chart shows.

Indeed, Mexico would have some advantages over a country such as Turkey, which trades very little with the US, according to Mr. Shearing.

US holidaymakers, for instance, would be likely to be tempted over the border to benefit from the weaker peso.

Debate rages as to whether the Trump administration will attempt to introduce a border tax or not. Mr. Saravelos argues it would be very inflationary, pushing up US consumer price inflation by five percentage points.

Paul Ashworth, chief US economist at Capital Economics, who labels the concept “equal parts genius and crazy,” says it simply would not be compliant with the rules of the World Trade Organization ( WTO), meaning that the US would need to convince the international community to change the rules, or else leave the WTO, in order to implement it.

His colleague Mr. Shearing says that US retailers, many of whom are reliant on imported goods and have thin margins, are “screaming blue murder” about the proposals.

Nevertheless, he notes that hopes among free traders that Mr. Trump’s “bark would be worse than his bite” on trade issues are waning, at least based on the president-elect’s tweets and his Cabinet choices, “all of which so far seem to be reliably bullish on trade.”

“It’s in the Ryan plan but there is broad sympathy for this in Trump circles,” Mr. Shearing adds.