This Python code reproduces the regressions in Tables 5-7 of Hull, Olovsson, Walentin, 
and Westermark (2020).


OS and Software Used:
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Mac OS 11.4
Python 3.7.4


Module Versions:
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numpy: 1.19.5
pandas: 0.25.1
statsmodels: 0.12.1


Instructions:
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Execute aggregate_regressions.py in Python.


Expected Computation Time:
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2.8 seconds