Except it is not a problem, it is a neutral condition

Many central banks reduced policy interest rates to zero during the global financial crisis to boost growth. Ten years later, interest rates remain low in most countries. While the global economy has been recovering, future downturns are inevitable. Severe recessions have historically required 3–6 percentage points cut in policy rates. If another crisis happens, few countries would have that kind of room for monetary policy to respond.To get around this problem, a recent IMF staff study shows how central banks can set up a system that would make deeply negative interest rates a feasible option.

The IMF simple told the staff to label it a problem, for whatever reason.

The problem the IMF is trying to solve, via fraud, is to get governments funded and out of their pressing debt. We know how to do that, in the most efficient manner, as in Lucas below, at the long term point, the point where Lucas becomes correct for once in his career, we devalue.

The goal, to do it slightly different this time, is for all parties to know as much of the story going into the meeting of the elders, and all parties are reasonably good at negotiation.  Hence the sandbox, we are in race; we need intelligent, always alert trading process for everyone, before the meeting of the elders.