## 4 Empirical Analysis
### Impulse-Response Function Analysis  
Finally, Figure 3 displays the results of the impulse-response test for global logistics companies in response to fluctuations in the GSCPI. The IRF analysis examines the reaction of global logistics companies to a one standard deviation shock in the GSCPI. First, it was found that most airline companies showed a slight decline in stock prices in the early stages. When global supply chain pressure occurs, Delta Air Lines will be affected by USD \(-\)0.608, USD \(-\)0.483, and USD \(-\)0.110 after 1 month, 2 months, and 3 months, respectively. After that, the impact will disappear significantly 4 months later. American Airlines Group will be affected by USD \(-\)0.398 one month later, and the effect will dramatically disappear after two months. United Airlines Holdings will be affected by USD \(-\)0.950, USD \(-\)0.855 and USD \(-\)0.221 after one month, two months, and three months, respectively. Finally, the Lufthansa Group will increase by EUR \(-\)0.069 after one month, while the impact will significantly reduce after two months by EUR 0.063 after three months.  
Next, when looking at comprehensive logistics companies, most of them are found to have significantly reduced stock prices after 3 months in. When the global supply chain pressure appears, United Parcel Service will be affected by a positive (+) of USD 0.477 and USD 0.245 after one month and two months, respectively. FedEx will be affected by USD \(-\)1.475 and USD \(-\)1.262 after one month and two months, respectively, and the impact after three months was significantly reduced to USD \(-\)0.282. DSV will be affected by SEK \(-\)3.050 and SEK \(-\)1.649 after one month and two months, respectively, and the effect converges to zero after three months.  
Looking at the comprehensive pipeline companies, most of them show a slight decline in stock prices in the early stages. When the global supply chain pressure occurs, Energy Transfer will be found to be very insignificant at USD \(-\)0.034 and USD 0.024 after one month and two months, respectively. Enterprise Products Partners, Plains GP Holdings, and Enbridge will be affected by USD \(-\)0.333, USD \(-\)0.254, and USD \(-\)0.190 after one month, respectively, and the effect will be found to be significantly reduced after two months. Cheniere Energy will be affected by USD \(-\)0.659 and USD \(-\)0.517 after one month and two months, respectively, and the effect will be found to be significantly reduced after three months.  
The results indicate that the shipping companies COSCO Shipping, Maersk Group, and Hapag-Lloyd all experience a positive (+) impact. Specifically, the largest impact occurs at Lag 2 (two months later), and this effect typically dissipates within three months. When the global supply chain pressure arises, COSCO Shipping will be affected by CNY 0.001 and CNY 0.184 after 1 month and 2 months, respectively, and the effect will be significantly reduced after 3 months. The Maersk Group will be affected by USD 0.065 and USD 0.286 after 1 month and 2 months, respectively, and the effect will be significantly reduced after  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Category** & **COSCO Shipping** & **Maersk Group** & **Hapag-Lloyd** \\ \hline GSCPI (\(-\)1) & **0.417379** & **0.688374** & **10.77264** \\  & **[1.83058]** & **[3.08136]** & **[1.61508]** \\  & **\(-\)0.217436** & **\(-\)0.223398** & \(-\)0.081045 \\  & **[\(-\)2.18559]** & **[\(-\)2.24790]** & **[\(-\)0.78566]** \\ Constant & 0.058710 & 0.025614 & 1.246611 \\  & [0.57296] & [0.25854] & [0.41778] \\ \hline \hline \end{tabular} Source: Authors’ own compilation. Note 1: Numbers in brackets represent t-statistics. Note 2: 1t-statistic \(\geq\) 2.368 = 99%, 1t-statistic \(\mid\)\(\geq\) 1.662 = 95%, 1t-statistic \(\mid\)\(\geq\) 1.291 = 90%.  
\end{table}
Table 9: VARM analysis results of comprehensive shipping companies.  
3 months of lag. Hapag-Lloyd will be affected by EUR 1.888 and EUR 4.581 after 1 month and 2 months, respectively, and the effect will be reduced after 3 months.