Could the correlation between yield curves and fiscal deficits and public debt disappear?

An increase in fiscal deficits or public debt is expected to lead to a steepening of the yield curve (we look at the situations of the United States, the euro zone and Japan). For this to no longer be the case, the central bank must have moved to “yield curve control”, i.e. a policy to stabilise the long-term interest rate, the upshot of which is that the central bank can then no longer control the size of its balance sheet. The Bank of Japan has officially adopted this policy, but it can still be conducted in practice without being official. A statistical and econometric analysis seems to show that yield curve control is being practised in Japan, but also in the United States and the euro zone. This policy is easier to conduct in the United States and Japan than in the euro zone, because the ECB is forced to put a cap on its bond purchase programmes.