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Omitted Variable Bias Supplied Covariance Term Tool

Calculate omitted variable bias supplied covariance term from explicit caller-supplied inputs.

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Description

bias = omittedEffect*covariance/includedVariance.

Regression model terms depend on the response link, variable scale and the meaning of coefficients. A local marginal effect, elasticity or model mean computed from supplied parameters does not estimate those parameters or establish causality.

bias = omittedEffect*covariance/includedVariance.

When to use this tool

Use Omitted Variable Bias Supplied Covariance Term when checking one stated regression-model contribution.

How to use the tool and how it works

  1. Enter omittedEffect, covariance, includedVariance. Use the units and conventions below.
  2. Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
  3. Read bias. Use the output convention below.

Require positive includedVariance. bias = omittedEffect*covariance/includedVariance.1

Input fieldMeaning and unitsAccepted input
omittedEffectOmitted EffectRequired. Finite number.
covarianceCovarianceRequired. Finite number.
includedVarianceIncluded VarianceRequired. Finite number; strictly above 0.
Output fieldInterpretationReturned shape
biasBiasRequired. Finite number.
json
{
  "input": {
    "omittedEffect": 2,
    "covariance": 3,
    "includedVariance": 4
  },
  "output": {
    "bias": 1.5
  }
}

Limitations and assumptions

  • The supplied covariance and variance must describe compatible variables, and omittedEffect the omitted variable's outcome slope. This local omitted-variable-bias identity does not identify confounding from data.
  • Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
  • Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use a fitted model, suitable data and defensible identification for prediction, inference and causal interpretation.

References

  1. Calculation and input contract: econometrics/omitted-variable-bias-supplied-covariance-term — tool.io

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