In his presentation today, he presents a system for evaluating and ranking different policy alternatives, showing how Taylor diagrams can be used to evaluate whether one interest rate forecast results in lower volatility in inflation and the output gap than another. If a forecast results in inflation closer to target and a narrower output gap through the forecast period, this forecast is selected. On other occasions, the choice between two forecasts can be more problematic. The forecast that is selected will depend on preference and the considerations that are given weight. I completely agree with Lars Svensson that policymakers must rank the different policy alternatives based on their preferences. In some cases, policymakers may wish to keep the interest rate high while in others a low interest rate may be preferred. However, it is equally important to take account of preferences over time, i.e. having a system to check whether the preferences underlying the baseline scenario in one report are the same as those of the previous report. And once preferences have been formalised in a loss function, it is relatively simple to find the optimal interest rate path for a given model. The choice of path will then depend on policymakers’ preferences. A policymaker’s preferences may of course change over time, but I am in favour of basing the analysis on the same set of preferences as previously. This approach will contribute to consistency in communication over time. 1  Cf.
Criteria 3, 4 and 5 introduce conditions that cannot easily be observed. We have to apply judgement. The criteria contribute to consistency and structure the discussion. The Riksbank also applies judgement when selecting the interest rate path. But Svensson does not discuss possible shortcomings in the macroeconomic model. In Chart 10, he shows how the various interest rate paths, differing by around ½ percentage point in the period to summer, could result in differences in the inflation rate of close to 4 percentage points as early as next autumn. Monetary policy seems to be having a very strong impact. It would be interesting to hear whether he thinks that relying so heavily on such a model in interest rate setting is robust, and how possible errors in the model should be guarded against. We also know from experience that market participants’ perceptions can differ from ours, particularly somewhat further ahead. There can be a variety of reasons for these differences and Svensson discusses a number of them. It would also be useful to study the volatility surrounding publication of key macroeconomic variables. We would prefer to see lower volatility around monetary policy meetings, and that any surprises are postponed to a time closer to the publication of new macroeconomic data. Solberg Johansen (2008) – winner of the Bertil Ohlin prize for best thesis in international economics at the Stockholm School of Economics – examines volatility in the yield curve.