We can clearly see the acting here: the mathematician who constructs an elegant equation and the Swiss National Bank which, all of a sudden, fractures this beautiful construction. While the proof establishes a sensitivity equivalence in an ideal world, it does not account for the fact that the behavior of pension funds is directly affected by monetary policy decisions, creating a reality where theory and practice meet abruptly, and the former generally gives way. That is why this equivalence only holds if the political volatility remains within reasonable bounds.