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. 2022 Oct 20;8(10):e11157. doi: 10.1016/j.heliyon.2022.e11157

Table 10.

Robustness test results.

Variables Exclusion of singular values
Replace explained variable
DPP IPP EP DPP IPP EP
0.0828∗∗ (0.0414) 0.107∗∗∗ (0.0371) 0.126∗ (0.0746) 0.0958∗∗ (0.0423) 0.0874∗∗ (0.0358) 0.192∗∗ (0.0766)
Control Yes Yes Yes Yes Yes Yes
Constant −15.01∗∗∗ (3.851) −15.38∗∗∗ (3.819) −15.90∗∗∗ (3.886) −13.15∗∗∗ (3.982) −13.63∗∗∗ (3.979) −14.42∗∗∗ (4.001)
Year Yes Yes Yes Yes Yes Yes
Province Yes Yes Yes Yes Yes Yes
Obs. 300 300 300 300 300 300
R2 0.877 0.879 0.877 0.867 0.867 0.867

Notes: t-statistics in parentheses. ∗∗∗p < 0.01. ∗∗p < 0.05. ∗p < 0.1.