There isn’t much that economists agree on, but it’s hard to find one who doesn’t believe the old investor adage that the phrase “this time is different” is one of the most dangerous in markets.

So why is it that a mention of the recent behaviour of one particular market phenomenon and its famed power to predict recession is almost always met with a response of “yes but”?

The indicator is known as the inversion of the yield curve — the line plotted between US Treasury bond yields on different maturities, most usually between two- and 10-year issues. It normally slopes upward to reflect the higher risk of lending for longer. When it inverts — that is, flips direction so longer-term yields are lower — it implies expectations that rates will fall to stimulate growth.