The University of Michigan measure slid in September, but most of the decline occurred before September 11 and was broadly consistent with the deterioration shown by the incoming economic data. This measure has remained fairly stable since then.
The Conference Board measure, on the other hand, declined sharply in October, but this sharper drop in the Conference Board measure brought it into closer alignment with the cumulative decline in the Michigan Index. So, surprisingly, at this point, whether September 11 significantly affected consumer confidence is unclear. At least, the effect is smaller than what many had expected.