This expenditure therefore needs an effective shield in the future, notably by allowing certain increases in investment when assessing compliance with the expenditure rule”. The European Commission made similar points in its own Review (EU Commission, 2020). 3/3  BIS central bankers' speeches
That means that the effect on the availability and terms of bank loans and subsequent impacts must be observed. This is especially true in a bank-dominated financial system such as the German one. Standard models used to assess the impact of monetary policy decisions, like the expectation augmented Phillips curve, need to model inflation expectations.