The forecasting method that Flyvbjerg applies is similar to the practices recommended for overcoming base-rate neglect: Identify an appropriate reference class (kitchen renovations, large railway projects, etc.). Obtain the statistics of the reference class (in terms of cost per mile of railway, or of the percentage by which expenditures exceeded budget). Use the statistics to generate a baseline prediction. Use specific information about the case to adjust the baseline prediction, if there are particular reasons to expect the optimistic bias to be more or less pronounced in this project than
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