Let Sc be the sum of squared residuals from the combined data, S1 be the sum of squared residuals from the first group, and S2 be the sum of squared residuals from the second group. N1 and N2 are the number of observations in each group and k is the total number of parameters (in this case, 3). Then the Chow test statistic is
[(Sc-S1-S2)/k] / [(s1+s2)/(N1+N2-2k)]
The test statistic follows the F ...
Let Sc be the sum of squared residuals from the combined data, S1 be the sum of squared residuals from the first group, and S2 be the sum of squared residuals from the second group. N1 and N2 are the number of observations in each group and k is the total number of parameters (in this case, 3). Then the Chow test statistic is
[(Sc-S1-S2)/k] / [(s1+s2)/(N1+N2-2k)]
The test statistic follows the F distribution with k and N1 + N2 − 2k degrees of freedom.