Another week, another wave of sabre-rattling from the Trump administration over trade. Two months ago, it was softwood lumber that grabbed the headlines: Wilbur Ross, US commerce secretary, announced tariffs on Canadian wood imports, arguing these were undercutting American rivals.
Now the focus is on steel. In the coming days Mr Ross is expected to issue a report outlining how cheap steel imports from countries such as China are hurting US companies, and undermining "national security" and jobs. This may well lead to US tariffs on steel - a threat that has already sparked an outcry from other world leaders, including Germany's Angela Merkel.
It is unclear how sweeping any tariffs will really be. But one thing is clear: White House officials urgently need to read some timely analysis from the Bank for International Settlements about the issue.
Normally, the BIS - which operates like a central banking club - does not talk much about trade, focusing instead on finance. But these days western central banks are fretting about protectionism. So the BIS included in its annual report, issued on Monday, a simulation of what might happen if the White House ever decided to impose a 10 per cent tariff on all imports from Mexico and China.
This reveals "a comparatively large sensitivity of US production costs to tariffs on imports from Mexico or China", the BIS says; more specifically, tariffs would hurt American-based companies in direct and indirect ways. The transport equipment sector would suffer most, followed by the leather, petroleum, textiles, machinery and electrical equipment sectors.
But what is really interesting - and thought-provoking for the White House, even if it is not actually threatening 10 per cent tariffs yet - is that BIS economists have also calculated the potential impact on labour costs. This suggests that if transport companies, such as carmakers, wanted to absorb the cost of these putative tariffs to keep their products competitive, they would have to cut wage costs by 6 per cent; for other industrial groups, a reduction of 2 and 4 per cent is needed.
This might imply lower wages. But the more likely response is that companies would just replace workers with more robots. After all, they already have from in this respect. As a fascinating recent paper by economists Daron Acemoglu and Pascual Restrepo shows, American industry has been replacing workers with robots on a startling scale in recent years, particularly in sectors such as car manufacturing (which has a third of all industrial robots).
Indeed, the economist Laura Tyson calculates, using Messrs Acemoglu and Restrepo's data, that robots have displaced 400,000 US manufacturing jobs each year in the past couple of decades - which has resulted in the manufacturing workforce falling by a third since 1997, even though output is at record high levels.
So if new tariffs and costs were imposed, there is every chance that executives would use this as an excuse to accelerate that automation. And just to add insult to injury, when American companies install industrial robots they tend to buy them from Germany and Japan, since these countries lead the world in advanced industrial robotics.
Thus far, the White House does not seem to have paid much - or any - attention to this. Instead, Mr Trump prefers to champion the idea of "made in America" production, at almost any cost. And, as luck would have it, he may actually get more of this in the coming years.
This week, the consultants McKinsey issued a report on US manufacturing that argues that the conditions are ripe for a renaissance in American industry, since "the world's value chains are in flux, which creates an opening for the United States to capture more production".
In particular "wages are rising in emerging economies, automation weakens the case for labour arbitrage, and the shale boom has made energy cheap and abundant" in the US. All of this could encourage reshoring.
But the rub is that industrial renaissance is not the same as job creation. On the contrary, the reason American companies are returning to the US is precisely their ability to cut labour costs. Or to put it another way, if those steel tariffs do emerge, they will boost the fortunes of US steel companies.
They may win some political slogans for Mr Trump too. But don't expect those tariffs to help many American workers. Instead the "winners" will be robots. However, those - of course - don't vote.
