[citation needed] This was used to argue against government intervention in political economy as a waste of time.
What money meant, or was equivalent to, became important as governments attempted to adjust interest rates rather than maintain the gold standard.
Actually, 20th century economics can be interpreted as a sequence of theoretical answers to the question whether money is only a veil or not.
The mechanisms through which money could exert these real effects were radically different and so were the sets of assumptions these authors created to establish their models.
In the case of rational expectations the monetary authority is not able to carry out systematic countercyclical economic policy – that is, it cannot exploit the existing short-run Phillips curve.