US President Donald Trump may have called tariffs his favourite word in the dictionary. But when it comes to obsessions, business investment has got to be close.

As of last month, he said more than $12 trillion (£8.8tn) had been "practically committed" on his watch. "Nobody's ever seen numbers like we have," he said, crediting his agenda of tariffs, tax cuts and deregulation with making the difference.

If true, the figure would indeed be astonishing, potentially tripling the roughly $4tn in gross private investment the US reported all of last year.

So is a sudden gush of business spending setting the stage for a new golden economic era as Trump claims, or is it all theatre?

First things first: it is too early in Trump's tenure to have clear data to evaluate his claims. The US government publishes statistics on business investment only every three months.