Contents -- I. INTRODUCTION AND SUMMARY -- II. DESCRIPTION OF WEO DATASET -- III. PROPERTIES OF OPTIMAL FORECASTS -- IV. EMPIRICAL RESULTS -- V. ANALYSIS OF STATISTICAL SIGNIFICANCE -- VI. CAN THE WEO FORECAST ERRORS BE PREDICTED? -- VII. DIRECTIONAL ACCURACY -- VIII. REVISIONS FROM BOARD TO PUBLISHED FORECASTS -- IX. RECENT PERFORMANCE OF WEO FORECASTS -- X. LONG-RUN FORECASTING PERFORMANCE FOR G-7 ECONOMIES -- XI. COMPARISON OF WEO AND CONSENSUS FORECASTS -- XII. FORECAST COMBINATIONS -- XIII. RECOMMENDATIONS -- XIV. CONCLUSION -- References.