When our first child was born, I had an office job. My wife’s exhausting and non-remunerated profession was stay-at-home mother. Later, she retrained as a portrait photographer. To let her return to the labour market, we needed to hire a nanny. There is more to such a decision than money but, on purely financial terms, this was a no-brainer: the nanny earned less than either of us, so by freeing us to earn money in other ways, the Harford household was richer as a result.

Yet what makes obvious sense for a household can become strange and threatening in a different context. Imagine: the proud independent nation of Harfordia had a thriving childcare sector (my wife), but it was undercut by cheap foreign competition (the nanny). There was a vast bilateral trade deficit with the nanny, and Harfordia’s homegrown childcare sector was devastated. Bad!

Though Harfordia’s photography sector boomed as a result, you can bet that’s not what the populists would be pointing to.