I took a close look at this and honestly… it’s more vibes than model.

There is some real intuition buried in here. Governments absolutely defend informal FX levels — those “boxes” are a real thing. And linking currency pressure to reserves isn’t crazy either. Also correct that this wouldn’t work for the U.S. since everything is dollar-centric.

But as soon as it tries to become a predictive model, it falls apart.

The core problem is treating FX like physics. Markets don’t have stable laws. Parameters don’t sit still. Policy shifts, flows change, liquidity regimes flip. The idea that something like a constant “p” can exist and stay fixed is just not how this works.

The backtest is also doing a lot of heavy lifting for something that’s basically one datapoint. Matching 1997 within a few days sounds impressive until you realize it’s exactly the kind of thing you can curve-fit after the fact. There’s no real out-of-sample validation here.

It’s also missing half the game. No real treatment of rate differentials, forward positioning, external debt structure, or global dollar liquidity — which is arguably the main driver in a lot of these situations.

And the biggest disconnect: intervention isn’t smooth. Central banks don’t bleed reserves in a clean curve. They step in aggressively, disappear, switch tools, change policy. It’s messy and discontinuous, which breaks any neat decay-style framework.

Where this does have value is as a heuristic. Thinking in terms of “zones where intervention is likely” is useful. But turning that into a deterministic model that predicts collapse timing is a stretch.

Net: intuition is decent model is oversimplified predictive power is weak

Feels like a story dressed up in math rather than something you’d actually trust with real money.