1.5 Hypothetical Model
Based on the related literature review，a model illustrating the structural relationships of SES，physical health，LTC level，and HALE to be tested in this study is proposed in Figure 1.12. This model includes three latent variables（SES，physical health status，and HALE）in the circles and one observed variable（LTC level）in the rectangle. A one-way arrow between two variables indicates a postulated direct influence of one variable on another. The following hypotheses（H1—H8）are established in the proposed study with various latent constructs.
H1：The level of SES will be positively associated with HALE directly（Figure 1.12：path ①）；
H2：The level of SES will be negatively associated with the LTC level directly（Figure 1.12：path ②）；
H3：The level of SES will be associated with the physical health status directly（Figure 1.12：path ③）；
H4：The physical health status will affect the LTC level directly（Figure 1.12：path ④）；
H5：The level of SES will affect HALE indirectly via LTC level（Figure 1.12：path ②—⑤）；
H6：The level of SES will affect HALE indirectly via physical health status（Figure 1.12：path ③—⑥）；
H7：The level of SES will affect HALE indirectly via physical health and LTC level（Figure 1.12：path ③—④—⑤）；
H8：Gender，age，and geographic differences exist in the structural relationships among SES，physical health，LTC level，and HALE.