. 2023 Feb 27;14:945487. doi: 10.3389/fpsyg.2023.945487

Table 4.

Testing of structural relationships and control variables in the TPAM and VAM.

Time perspective activation model (TPAM)			Value activation model (VAM)
Paths	Standardized coefficients	t-values	Paths	Standardized coefficients	t-values
Direct effects
HV → future	0.21	4.14***	Future → HVs	0.19	4.24***
	0.22	4.95***		0.17	3.65***
HV → present	0.39	7.17***	Present → HVs	0.37	7.41***
	0.56	11.28***		0.51	10.17***
BV → future	0.24	5.04***	Future → BVs	0.27	6.12***
	0.47	10.89***		0.55	11.76***
BV → present	0.09	1.92^ns	Present → BVs	0.18	3.88***
	0.07	1.63^ns		0.04	0.95^ns
HV → WTP	−0.35	−6.36***		−0.35	−6.36***
	−0.29	−4.76***		−0.29	−4.76***
BV → WTP	0.37	7.49***		0.37	7.49***
	0.39	7.00***		0.39	7.00***
Future → WTP	0.09	1.92^ns		0.09	1.92^ns
	0.02	0.34^ns		0.02	0.34^ns
Present → WTP	0.08	1.61^ns		0.08	1.61^ns
	−0.02	−0.04^ns		−0.02	−0.41^ns
*Indirect effects*
HVs → future → WTP	0.021/0.002 (0.011/0.012)^a	1.91^ns	Future → HVs → WTP	−0.066/−0.049 (0.018/0.020)^a	−3.69***
		0.17^ns			2.45**
HVs → present→ WTP	0.039/−0.010 (0.022/0.034)^a	1.77^ns	Present → HVs → WTP	−0.129/−0.148 (0.028/0.033)^a	4.63***
		−0.29^ns			4.48***
BVs → future → WTP	0.022/0.005	1.83^ns	Future → BVs → WTP	0.099/0.215 (0.017/0.036)^a	5.88***
	(0.012/0.025)^a	0.20^ns			5.96***
BVs → present → WTP	0.009/−0.001 (0.007/0.005)^a	1.29^ns	Present → BVs → WTP	0.067/0.017 (0.018/0.018)^a	3.70***
		−0.20^ns			0.87^ns
*Controlled variables*
Age → WTP	−0.22	−5.41***		−0.22	−5.41***
	−0.22	−5.40***		−0.22	−5.39***
Gender → WTP	−0.06	−1.53^ns		−0.06	−1.53^ns
	−0.06	−1.49^ns		−0.06	−1.49^ns
Marital status → WTP	0.02	0.63^ns		0.02	0.63^ns
	0.03	0.73^ns		0.03	0.74^ns
Education → WTP	0.11	2.85**		0.11	2.85**
	0.11	2.89**		0.11	2.88**
Weight → WTP	−0.03	−0.66^ns		−0.03	−0.66^ns
	−0.03	−0.65^ns		−0.03	−0.63^ns
*Fit indices*
Chi-squared (df)	579.82 (216)/446.82 (176)			579.82 (216)/446.82 (176)
GFI	0.924/0.035			0.924/0.935
CFI	0.948/0.962			0.948/0.962
RMSEA	0.052/0.049			0.052/0.049
AIC	699.823/556.818			699.823/556.812
R² (WTP)	21.7%/20.4%			21.7%/20.4%

The standardized errors of indirect effects were estimated using bootstrapping.

HVs, hedonic values; BVs, biospheric values; WTP, willingness to pay. The results for the Temporal Importance Scale are in bold. ^nsp > 0.05; *p < 0.05; **p < 0.01; ***p < 0.001.