the behavior of the variables under study. Historical data and assumptions about the future are applied to the model in arriving at a forecast for particular variables. Sources of forecasts Global scope The Economic Outlook is the OECD's twice-yearly analysis of the major economic trends and prospects for the next two years. The IMF publishes the World Economic Outlook report twice annually, which provides comprehensive global coverage. The IMF and World Bank also produces Regional Economic Outlook for various parts of the world. There are also private companies such as The Conference Board and Lombard Street Research that provide global economic forecasts. U.S. forecasts The U.S. Congressional Budget Office (CBO) publishes a report titled "The Budget and Economic Outlook" annually, which primarily covers the following ten-year period. The U.S. Federal Reserve Board of Governors members also give speeches, provide testimony, and issue reports throughout the year that cover the economic outlook. Regional Federal Reserve Banks, such as the St Louis Federal Reserve Bank also provide forecasts. Large banks such as Wells Fargo and JP Morgan Chase provide economics reports and newsletters. European forecasts The European Commission also publishes comprehensive macroeconomic forecasts for its member countries on a quarterly basis - Spring, Summer, Autumn and Winter. Combining Forecasts Forecasts from multiple sources may be arithmetically combined and the result is often referred to as a consensus forecast. Private firms, central banks, and government agencies publish a large volume of forecast information to meet the strong demand for economic forecast data. Consensus Economics compiles the macroeconomic forecasts prepared by a variety of forecasters, and publishes them every month. The Economist magazine regularly provides such a snapshot as well, for a narrower range of countries and variables. Econometric studies have demonstrated that the use of past errors of each original forecast to determine the weights assigned to each forecast in the creation of a combined forecast results in a composite set of forecasts that generally yield to lower mean-square errors compared to either of the individual original forecasts. However, it has been found that the entry and exit of forecasters can have a substantial impact on the real-time effectiveness of conventional combination methods. The dynamic nature of the forecasting combination and adjusting weighting techniques is not neutral. Forecast methods The process of economic forecasting is similar to data analysis and results in estimated values for key economic variables in the future. An economist