“…First, following Friedman (1953), the common themes and other results that I document may provide for a wider range of assumptions within traditional models, some of which might lead to improved predictability. Second, for those who favor the subset of realistic assumptions, knowing which assumptions and processes 21 Altig et al (2020), based on several hundred monthly responses from financial executives, and Bloom et al (2020), based on a Census question answered by managers at more than 30,000 plants, find that the 10 th (90 th ) percentile forecast aligns with the "lowest" ("highest") forecast when respondents probability-weight five possible future outcomes: lowest, low, middle, high, and highest. That is, these respondents assign a 10% probability of the "lowest" and "highest" forecasts occurring.…”