Even Fisher Black admits that there is a currency trap at 0% and he doesn't mean that the problem is that the interest rate is too low but rather that the zero

Even Fisher Black admits that there is a currency trap at 0% and he doesn't mean that the problem is that the interest rate is too low but rather that the zero lower bound is like a minimum price control that constraints the formation of interest rates and he basically predicted what the IMF blog Said about this resulting in cash and electronic bank accounts ending up with an exchange rate between them.