Table 5. Relative importance of the predictors of happiness by age group.

	19–29 years			30–39 years				40–59 years				≥ 60 years
Variable	SV	%R2	95% CI	SV	%R2	95% CI		SV	%R2	95% CI		SV	%R2	95% CI
Sex	0.005	3.37	(2.90, 4.90)	0.001	0.95	(0.75, 1.71)		0.001	0.71	(0.60, 1.09)		0.001	0.52	(0.49, 0.66)
Education level	0.002	1.67	(1.36, 2.95)	0.011	7.73	(7.09, 9.97)		0.021	13.38	(12.78, 14.80)		0.019	11.15	(10.69, 12.43)
Marital status	0.009	6.07	(5.39, 7.98)	0.034	23.79	(22.69, 26.76)		0.028	18.45	(17.80, 20.15)		0.007	3.91	(3.68, 4.66)
Live alone (yes)	0.000	0.11	(0.06, 0.47)	0.005	3.41	(3.04, 4.58)		0.007	4.62	(4.34, 5.47)		0.004	2.40	(2.21, 2.93)
Employment status	0.000	0.09	(0.08, 0.51)	0.003	2.21	(1.90, 3.39)		0.004	2.34	(2.14, 3.05)		0.002	1.11	(1.03, 1.39)
Log household income	0.001	0.33	(0.19, 0.93)	0.001	0.79	(0.59, 1.40)		0.000	0.28	(0.21, 0.54)		0.000	0.13	(0.09, 0.27)
Subjective health status	0.104	72.32	(70.47, 75.26)	0.068	47.06	(45.29, 50.42)		0.070	45.64	(44.70, 47.76)		0.096	57.25	(56.45, 59.25)
Contact frequency with relative/family	0.007	4.70	(4.27, 6.61)	0.011	7.65	(7.08, 9.70)		0.010	6.19	(5.82, 7.30)		0.014	8.09	(7.74, 9.26)
Contact frequency with neighbor	0.006	3.98	(3.63, 5.40)	0.005	3.59	(3.28, 4.98)		0.006	4.12	(3.86, 4.98)		0.007	4.44	(4.20, 5.31)
Contact frequency with friend	0.011	7.35	(6.73, 9.80)	0.004	2.80	(2.51, 4.29)		0.007	4.28	(4.00, 5.33)		0.018	11.00	(10.59, 12.26)
Total R2	0.144	100		0.144	100			0.154	100			0.167	100

Abbreviations: SV, Shapley value; CI, confidence interval.

%R² represents the relative importance value.