Durbin-Watson Upper and Lower Bound Calculator
Introduction & Importance
The Durbin-Watson test is a statistical test used to detect autocorrelation in the residuals of a regression model. The upper and lower bounds are critical for determining the significance of the test results.
How to Use This Calculator
- Enter the value of T (the number of observations).
- Enter the significance level (alpha).
- Enter the number of observations (N).
- Click ‘Calculate’.
Formula & Methodology
The Durbin-Watson statistic (d) is calculated as:
d = (∑etet-1) / (∑et2)
The upper and lower bounds are calculated using the following formulas:
Upper bound = 4(1 – α) / N
Lower bound = 4α / N
Real-World Examples
Data & Statistics
| N | α = 0.05 | α = 0.01 |
|---|
Expert Tips
- Always check for autocorrelation before and after applying any correction methods.
- Consider using the Breusch-Godfrey test for higher-order autocorrelation.
Interactive FAQ
What is autocorrelation?
Autocorrelation is a statistical phenomenon where the residuals of a regression model are correlated with each other.