It is thus possible to collect information on new economic and financial developments, such as the impact of recent changes in the price of oil. Other attractive features of online surveys are the ease of incorporating graphics and other visual refinements and the ease of conducting randomized interactive experiments to analyze the updating of expectations and the links between expectations and behavior. A second key design element of the SCE is that it uses a rotating-panel sample design, with approximately 1/12 of respondents rotating in each month, after which they stay in the panel for up to 12 months and then rotate out. In addition to keeping the sample representative over time, this rotational structure allows us to track the changes in individuals’ responses over time. In other words, we can compute changes in expectations over time after differencing out individual idiosyncratic effects. This design contrasts with repeated crosssectional surveys in which an entirely new sample is drawn each month. The panel structure of our survey, with a more stable sample composition, therefore reduces volatility in summary statistics due to a changing sample and increases the signal-to-noise ratio. Finally, it is possible to use the panel to link short-term expectations to actual realizations, and measure individual-level forecast accuracy and its implications in real time.
1 See Article 127 of The Treaty on the Functioning of the European Union. 2 Jean-Claude Trichet, 2014: “Central Banking in the Crisis: Conceptual Convergence and Open Questions on  Unconventional Monetary Policy” Business Economics, Palgrave Macmillan; National Association for Business Economics, Vol. 49(2), pp. 74–84, April. www.perjacobsson.org/lectures/101213.pdf 3 Kydland, F. and E. Prescott (1977) “Rules rather than discretion: The inconsistency of optimal plans”, Journal of  Political Economy, 85(3), pp. 473–92. 4 Alesina, A. and L. Summers (1993) “Central bank independence and macroeconomic performance: Some  comparative evidence”, Journal of Money, Credit and Banking 25(2), pp. 151–162. 5 December 2018 Eurosystem staff macroeconomic projections for the euro area. 6 OECD Economic Outlook, November 2018. 7 Bank for International Settlements: Credit to non-financial corporations from all sectors at market value –  Percentage of GDP. March 2006 – June 2018 (unconsolidated data). 8 “The cost of deficiencies in euro-area economic policy coordination” Quarterly Selection of Articles No. 46,  Banque de France, summer 2017. 9 Address given by Pierre Werner, Luxembourg Prime Minister and Foreign Minister, on 30 September 1965 to the  Belgian Chamber of Commerce in New York. 6/6  BIS central bankers' speeches