Hausman-Wu Test
Calculate a regression-based Hausman-Wu test for the endogeneity of suspect_ticker in a regression of dependent_ticker on suspect_ticker (and, optionally, other_independent_tickers), using instrument_tickers as instruments for suspect_ticker.
Also known as: Hausman test, Durbin-Wu-Hausman test, regression test for endogeneity.
For more information about the method, see hypothesis_testing_model.get_hausman_wu_test.
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Calculate the Hausman-Wu Test in Python
The Hausman-Wu Test is available in the Econometrics module of the open-source Finance Toolkit. Install it with:
pip install financetoolkit -U
Then call get_hausman_wu_test as shown below.
from financetoolkit import Toolkit
toolkit = Toolkit(["AAPL", "MSFT"], api_key="FINANCIAL_MODELING_PREP_KEY")
toolkit.econometrics.get_hausman_wu_test(
"AAPL", "MSFT", "Benchmark", period="weekly"
)
Which returns:
| Metric | Value |
|---|---|
| V-Hat Coefficient | -0.7162 |
| T-Statistic | -6.6098 |
| Degrees of Freedom | 154 |
| P-Value | 0.0000 |
| Endogenous (5%) | 1 |
Parameters
get_hausman_wu_test accepts the following parameters:
- dependent_ticker (str): The dependent (predicted) asset.
- suspect_ticker (str): The (possibly endogenous) asset being tested.
- instrument_tickers (str | list[str]): One or more instrument asset(s) for
suspect_ticker– assets correlated withsuspect_tickerbut assumed uncorrelated withdependent_ticker’s error term. - other_independent_tickers (str | list[str] | None, optional): Any other (assumed exogenous) independent asset(s) to include. Defaults to None.
- period (str, optional): The data frequency (daily, weekly, monthly, quarterly, or yearly). Defaults to “daily”.
- column (str, optional): The historical data column to regress on. Defaults to “Return”.
- rounding (int | None, optional): The number of decimals to round the results to. Defaults to None.
Related Specification Tests
The Econometrics module page introduces the module, and the sidebar lists all of its functions.