One of the unintended consequences of global central banks' race to the bottom (which seemingly has no bottom) is that negative interest rates act as a tax on the banking system. By penalizing commercial lenders for parking their reserves at the central bank, it erodes the profit margin they make on charging already low interest rates while raising the cost of capital.
So far, "banks seem unable or unwilling to pass negative deposit rates to their retail customers, leaving them with few options to offset costs", note analysts at JP Morgan.
They also highlight that, should banks start imposing higher lending costs on their customers, this would have the reverse effect of easy monetary policy, crimping credit creation and tightening financial conditions.
All of this begs the question of whether the world has hit the limits of what monetary policy can achieve, as the distortions produced by sub-zero rates overwhelm its stimulatory benefits.
The current global recovery has been one of the most deflationary in modern times. Over the last six-and-a-half years, the nominal GDP of the advanced world - or the total cash value of their economies - has grown by just 11pc, according to Bank of America Merrill Lynch.
Meanwhile, more than $8 trillon of high grade sovereign debt is trading at a negative yield.
Distortions such as this have led prominent monetary policymakers to dub the move into negative interest rates a "gigantic fiscal policy failure".
Eight years on the from the financial crisis, central banks have done all the heavy lifting to get the world out of its low growth morass. Monetary policymakers have cut interest rates 637 times and purchased $12.3 trillion (£8.5 trillion) of assets since March 2008.
Mario Draghi, president of the European Central Bank, bemoans that his institution has provided the sole source of stimulus to the eurozone over the last six years. He renewed his calls for governments to finance mass public investment schemes and cut tax burdens to reflate their economies this week.
So although negative interest rates may herald new danger for financial markets, they could well be the catalyst jolting politicians and governments into finally making use of powerful fiscal policy tools to rescue the world from the grips of another slump.
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