Table 3.
Estimated coefficients of variables in the ITS model (Dependent variable: daily CBM volume from Hong Kong to Shenzhen).
| CBM | From Hong Kong to Shenzhen | |||
|---|---|---|---|---|
| Variables | Coef. | St.Err. | p value | |
| Pre-pandemic level and trend | ||||
| Day (the trend over time) | -0.11 *** | 0.03 | 0.00 | |
| Early old age (55–59, as reference, the level on day 0) | 90.66 *** | 1.18 | 0.00 | |
| Middle old age (60–64, compared to early old age) | −43.49 *** | 1.08 | 0.00 | |
| Old age (65+, compared to early old age) | −39.79 *** | 1.08 | 0.00 | |
| The abrupt effects on CBM flows during four stages among three senior groups | ||||
| Stage #1: Warning Stage | Early old age (as reference, the level change in the Stage #1) | −5.60 | 3.42 | 0.10 |
| Middle old age (compared to early old age) | 5.01 | 4.09 | 0.22 | |
| Old age (compared to early old age) | 5.40 | 4.09 | 0.19 | |
| Stage #2: Freezing Stage | Early old age (as reference, the level change in the Stage #2) | −54.68 *** | 2.74 | 0.00 |
| Middle old age (compared to early old age) | 24.58 *** | 2.47 | 0.00 | |
| Old age (compared to early old age) | 21.87 *** | 2.47 | 0.00 | |
| Stage #3: Adjustment Stage | Early old age (as reference, the level change in the Stage #3) | −44.55 *** | 2.45 | 0.00 |
| Middle old age (compared to early old age) | 16.95 *** | 1.85 | 0.00 | |
| Old age (compared to early old age) | 19.15 *** | 1.85 | 0.00 | |
| Stage #4: Recovery Stage | Early old age (as reference, the level change in the Stage #4) | −8.14 * | 4.39 | 0.06 |
| Middle old age (compared to early old age) | 4.83 ** | 2.44 | 0.05 | |
| Old age (compared to early old age) | 2.66 | 2.44 | 0.28 | |
| The gradual effects on CBM flows during four stages among three senior groups | ||||
| Stage #1 × Time #1: Warning Stage | Early old age (as reference, the slope change in the Stage #1) | −4.53 *** | 0.68 | 0.00 |
| Middle old age (compared to early old age) | 2.16 *** | 0.84 | 0.01 | |
| Old age (compared to early old age) | 2.33 *** | 0.84 | 0.01 | |
| Stage #2 × Time #2: Freezing Stage | Early old age (as reference, the slope change in the Stage #2) | 0.04 | 0.13 | 0.78 |
| Middle old age (compared to early old age) | −0.09 | 0.13 | 0.49 | |
| Old age (compared to early old age) | −0.03 | 0.13 | 0.81 | |
| Stage #3 × Time #3: Adjustment Stage | Early old age (as reference, the slope change in the Stage #3) | 0.38 *** | 0.05 | 0.00 |
| Middle old age (compared to early old age) | −0.01 | 0.04 | 0.88 | |
| Old age (compared to early old age) | −0.13 *** | 0.04 | 0.00 | |
| Stage #4 × Time #4: Recovery Stage | Early old age (as reference, the slope change in the Stage #4) | 0.05 | 0.11 | 0.61 |
| Middle old age (compared to early old age) | 0.05 | 0.12 | 0.71 | |
| Old age (compared to early old age) | 0.15 | 0.12 | 0.24 | |
| Control Variables | ||||
| Gender | Early old age (the difference between male and female) | −38.74 *** | 0.96 | 0.00 |
| Middle old age (compared to early old age) | 18.91 *** | 0.96 | 0.00 | |
| Old age (compared to early old age) | 22.10 *** | 0.96 | 0.00 | |
| Holiday | −0.57 | 1.07 | 0.60 | |
| HK_Cases | −0.03 | 0.02 | 0.16 | |
| SZ_Cases | −0.11 ** | 0.05 | 0.02 | |
| Monday | 1.83 ** | 0.73 | 0.01 | |
| Tuesday | 2.52 *** | 0.73 | 0.00 | |
| Wednesday | 3.28 *** | 0.73 | 0.00 | |
| Thursday | 2.90 *** | 0.73 | 0.00 | |
| Friday | 4.46 *** | 0.73 | 0.00 | |
| Saturday | 2.22 *** | 0.73 | 0.00 | |
| Mean dependent var | 30.152 | SD dependent var. | 21.053 | |
| Number of obs | 1,098 | Chi-square | 10502.763 | |
| Prob > chi2 | 0.000 | Akaike crit. (AIC) | 7313.644 | |
Robust standard errors in parentheses: *** p < 0.01, ** p < 0.05, * p < 0.1.