# “The impact of September 11 on Air Travel in the US”

In this homework, we use the data on textbook Page 107 “The impact of September 11 on Air Travel in the US”. Data details are described on Page 107 for reference.

## “The impact of September 11 on Air Travel in the US”

In this homework, we use the data on textbook Page 107 “The impact of September 11 on Air Travel in the US”. Data details are on Page 107 for reference. This homework requires SPSS analyses (R is acceptable as well, Excel cannot perform the analyses below). Our first step is data partition: split the time series into two parts, pre-September 11 and post-September 11. (Do not forget define time-series data.)

a) Fit a linear regression models to Air, Rail, and Auto. For Air and Auto, fit a linear trend. For Rail, use a quadratic trend. Report ANOVA results as well. Discuss the results.

b) Run a seasonal decomposition for Air series with multiplicative seasonality and show the results output.

c) Which of the following smoothing methods would be adequate for forecasting this series? Discuss your results.

Firstly, simple exponential smoothing.

Secondly, holt’s linear exponential smoothing

### More details;

No industry has suffered greater economic damage from the terrorist attacks of September 11, 2001 than the U.S. airline industry. In addition to directly causing a temporary but complete shut-down of the commercial aviation system, the attacks caused many travelers to reduce or avoid air travel, weary of a newly-perceived risk associated with flying. Likewise, following September 11, many businesses put temporary freezes on all but the most essential travel for their employees.

And although the initial “panic” driven fear of flying immediately following September 11 appears to have largely dissipated. The stringent new security requirements that were implement as a direct result of the terrorist attacks have made traveling by air more cumbersome and time-consuming than prior to September 11. The purpose of this paper is to examine the impact of September 11 on U.S. airline demand and to determine whether or not September 11 and its after-effects have resulted in a negative shift in the demand for air travel.