Methodology: Bloomberg Rankings used estimates submitted to Bloomberg for 14 key monthly economic indicators. They are: Consumer Price Index, Durable Goods Orders, Existing Home Sales, Gross Domestic Product, Housing Starts, Industrial Production, Institute of Supply Management Manufacturing Index, Institute of Supply Management Nonmanufacturing Index, New Home Sales, Nonfarm Payrolls, Personal Income, Personal Spending, Retail Sales, and Unemployment. Gross Domestic Product is treated as a monthly indicator by ranking the advance, second and third revisions.
Bloomberg considered two years of data (ending with estimates for February 2014) for monthly indicators, with a forecast requirement of at least 15 out of 24 forecasts, a minimum of two consecutive forecasts within the last six months and at least one forecast in the last three periods. Each indicator had at least 62 forecasters who qualified for the ranking.
This ranking does not include the Producer Price Index. The Labor Department changed the definition of the PPI in February, and the minimum 24 months of data on which to rank forecasters wasn't available.
Bloomberg assigned a score between zero and 100 to the economists, reflecting the accuracy of their historical forecasts. Economists with lower forecast errors relative to other economists would receive higher scores, and vice versa. To identify the best overall forecaster, we averaged the scores of the 68 forecasters who qualified in at least eight indicators.