For all these reasons, it seems important from a policy perspective to develop and employ non-linear modelling and estimation techniques. IV. Concluding remarks  To sum up, over the past decades, tremendous progress has been made towards making monetary policy more of a science. Undoubtedly, this has contributed to enhancing the effectiveness of monetary policy.
At the same time, there is still room – and indeed a need – to further advance the scientific elements of monetary policy-making by addressing a number of conceptual, methodological and empirical challenges. Some of these challenges are a consequence of the nature of the economic system and the uncertainty surrounding its evolution over time.