Does the Power of Social Example Fade? Nudge Effect of Social Information on Individual’s Donation Behaviors During the COVID-19 Pandemic: A Moderated Mediation Model with Three-Wave Cross-Sectional Data

Figures & data

Figure 1 Hypothesized moderated mediation model.

Table 1 Descriptive Statistics of the Demographic Variables

Variable	Categorization	Frequency (Percentage)				K-W
		All	T1	T2	T3	Sig.
Gender	Male	575 (41.9%)	273 (39.0%)	136 (42.2%)	166 (47.6%)	0.030
	Female	796 (58.1%)	427 (61.0%)	186 (57.8%)	183 (52.4%)
Age	18–20	373 (27.2%)	204 (29.1%)	91 (28.2%)	88 (25.2%)	0.123
	21–25	574 (41.9%)	291 (41.6%)	136 (42.2%)	138 (39.5%)
	26–30	228 (16.6%)	113 (16.1%)	49 (15.2%)	65 (18.6%)
	>30	196 (14.3%)	92 (13.1%)	46 (14.3%)	58 (16.6%)
Polity	Communist Party	275 (20.1%)	130 (18.6%)	64 (19.9%)	81 (23.1%)	0.209
	Otherwise	1096 (79.9%)	570 (81.4%)	258 (80.1%)	268 (76.8%)
Sibling	0	534 (39.0%)	262 (37.4%)	130 (40.4%)	142 (40.7%)	0.103
	1	348 (25.4%)	175 (25.0%)	79 (24.5%)	94 (26.9%)
	2	331 (24.1%)	166 (23.7%)	71 (22.1%)	94 (26.9%)
	≥3	158 (11.5%)	97 (13.9%)	42 (13.0%)	19 (5.4%)
Fam-income	RMB 0–3000	350 (25.5%)	189 (27.0%)	84 (26.1%)	77 (22.1%)	0.193
	RMB 3001–6000	494 (36.0%)	254 (36.3%)	115 (35.7%)	125 (35.8%)
	RMB 6001–9000	170 (12.4%)	77 (11.0%)	43 (13.4%)	50 (14.3%)
	> RMB 9000	357 (26.0%)	180 (25.7%)	80 (24.8%)	97 (27.8%)
Ind-expenditure	RMB 0–1000	416 (30.3%)	217(31.0%)	101 (31.4%)	98 (28.1%)	0.536
	RMB 1001–2000	566 (41.3%)	290 (41.4%)	131 (40.7%)	145 (41.6%)
	RMB 2001–3000	171 (12.5%)	85 (12.1%)	37 (11.5%)	49 (14.0%)
	> RMB 3000	218 (15.9%)	108 (15.4%)	53 (16.5%)	57 (16.3%)

Table 2 Descriptive Statistics of Social-Anxiety and Self-Control

Variables	Pandemic Status	MEAN	SD	MAX	MIN
Socialanx	T1	50.256	12.728	89	18
	T2	43.475	13.787	88	15
	T3	47.648	14.611	86	19
	Total	47.999	13.743	89	15
Selfcontrol	T1	52.3857	13.814	95	19
	T2	53.037	11.377	81	22
	T3	48.699	12.848	88	21
	Total	51.600	13.137	95	19

Figure 2 Participants’ donation behaviors at different pandemic stages.

Table 3 Test of the Nudge Power of Social Information Along with the Pandemic Status

Type of Social Information	Power of Social Information	Time (Frequency/Percentage)
		T1	T2	T3
Type = 0 (Baseline condition)	Power = 0	124/89.9%^a	43/91.5%^a	38/90.5%^a
	Power = 1	14/10.1%^a	4/8.5%^a	4/9.5%^a
	Total	138/100%	47/100%	42/100%
	Fisher’s Exact Test, p = 1.000
Type = 1 (Negative condition)	Power = 0	228/81.5%^a,b	95/85.6%^a	105/72.4%^b
	Power = 1	51/18.3%^a,b	16/14.4%^a	40/27.6%^b
	Total	279/100%	111/100%	145/100%
	χ^2 = 7.896, p = 0.019
Type = 2 (Positive condition)	Power = 0	193/68.2%^a	132/80.5%^b	125/77.2%^a,b
	Power = 1	90/31.8%^a	32/19.5%^b	37/22.8%^a,b
	Total	283/100%	164/100%	162/100%
	χ^2 = 9.352, p = 0.009

Notes: We conducted Fisher’s Exact Test in the Baseline condition because two expected frequencies were below 5 in this condition. All the expected frequencies in other conditions were above 5. Superscripts indicate the results of pairwise comparisons with Bonferroni adjustment. The different superscript letters, for example ^a,bIndicated that there was significant difference between the two frequencies (p<0.05).

Figure 3 Effects of social information.

Table 4 Logit Regression Results

Condition	Path	Coefficient	p-value	95% CI
Type = 0 (Baseline)	Pandemic Status T1–T2→Power	−0.115	0.848	[−1.295, 1.065]
	Pandemic Status T2–T3→Power	−0.076	0.934	[−1.874, 1.722]
Type = 1 (Negative)	Pandemic Status T1–T2→Power	−0.310	0.349	[−0.957, 0.338]
	Pandemic Status T2–T3→Power	1.745	0.001	[0.752, 2.738]
Type = 2 (Positive)	Pandemic Status T1–T2→Power	−0.670	0.007	[−1.154, −0.186]
	Pandemic Status T2–T3→Power	−0.214	0.643	[−1.120, 0.691]

Notes: CI, confidence interval. The demographic variables Gender, Age, Sibling, Polity, Fam-income, and Ind-expenditure were included as control variables in the regressions.

Table 5 Results for the Mediating Role of Social Anxiety

Condition	Path	Effect	95% CI
Type = 1 (Negative)	X (Pandemic Status T2–T3)→M (Socialanx)→Y (Power)
	Total effect of X on Y	0.238	[0.102, 0.351]
	Average direct effect of X on Y	0.088	[−0.030, 0.192]
	Average causal mediation effect of M	0.150	[0.075, 0.228]
Type = 2 (Positive)	X (Pandemic Status T1–T2)→M (Socialanx)→Y (Power)
	Total effect of X on Y	−0.132	[−0.216, −0.046]
	Average direct effect of X on Y	−0.058	[−0.135, 0.026]
	Average causal mediation effect of M	−0.074	[−0.107, −0.043]

Notes: The demographic variables Gender, Age, Sibling, Polity, Fam-income, and Ind-expenditure were included as control variables in the regressions.

Abbreviation: CI, confidence interval.

Table 6 Results for the Moderated Mediation Effect of Self-Control in the Negative Condition

Variable	B	SE	p-value	95% CI
Outcome variable: Socialanx
Pandemic Status T2–T3	51.478	8.730	< 0.001	[34.283, 68.673]
Selfcontrol	−0.076	0.113	0.501	[−0.298, 0.146]
Pandemic Status T2–T3 × Selfcontrol	−0.675	0.139	< 0.001	[−0.948, −0.402]
Gender	1.322	1.627	0.417	[−1.883, 4.527]
Age	−0.192	0.166	0.247	[−0.518, 0.134]
Polity	1.817	2.058	0.378	[−2.237, 5.871]
Sibling	0.687	0.763	0.369	[−0.816, 2.190]
Fam-income	−0.020	0.062	0.744	[−0.143, 0.102]
Ind-expenditure	−0.026	0.168	0.879	[−0.356, 0.305]
Outcome variable: Power
Pandemic Status T2–T3	11.673	3.190	< 0.001	[5.420, 17.926]
Selfcontrol	0.181	0.029	< 0.001	[0.124, 0.237]
Socialanx	0.175	0.046	< 0.001	[0.085, 0.264]
Pandemic Status T2–T3 × Selfcontrol	−0.174	0.050	0.001	[−0.271, −0.076]
Gender	0.065	0.485	0.893	[−0.885, 1.016]
Age	0.47	0.246	0.056	[−0.012, 0.951]
Polity	−0.105	0.047	0.024	[−0.196, −0.014]
Sibling	0.983	0.543	0.071	[−0.082, 2.048]
Fam-income	−0.062	0.032	0.054	[−0.125, 0.001]
Ind-expenditure	0.083	0.052	0.109	[−0.019, 0.185]
Conditional indirect effect: Pandemic Status T2–T3→Socialanx→Power
Selfcontrol	B	BootSE	BootLLCI	BootULCI
M-1SD	3.171	1.185	2.097	6.322
M	1.621	0.749	0.807	3.565
M+1SD	0.071	0.726	−1.273	1.612
Conditional direct effect: Pandemic Status T2–T3→Power
Selfcontrol	B	SE	LLCI	ULCI
M-1SD	2.953	0.907	1.175	4.730
M	0.744	0.667	−0.563	2.050
M+1SD	−1.465	0.933	−3.295	0.364
Index of moderated mediation
	Index	BootSE	BootLLCI	BootULCI
Selfcontrol	−0.122	0.050	−0.250	−0.066

Abbreviations: B, unstandardized coefficient; SE, standard error; CI, confidence interval; LL, lower limit; UL, upper limit.

Table 7 Results for the Moderated Mediation Effect of Self-Control in the Positive Condition

Variable	B	SE	p-value	95% CI
Outcome variable: Socialanx
Pandemic Status T1–T2	−39.636	6.15	< 0.001	[−51.723, −27.549]
Selfcontrol	−0.491	0.052	< 0.001	[−0.594, −0.389]
Pandemic Status T1–T2 × Selfcontrol	0.543	0.099	< 0.001	[0.349, 0.738]
Gender	3.071	1.185	0.010	[0.743, 5.400]
Age	−0.099	0.127	0.434	[−0.349, 0.150]
Polity	1.36	1.646	0.409	[−1.875, 4.595]
Sibling	0.627	0.453	0.167	[−0.264, 1.517]
Fam-income	−0.038	0.105	0.722	[−0.245, 0.170]
Ind-expenditure	−0.176	0.584	0.763	[−1.324, 0.972]
Outcome variable: Power
Pandemic Status T1–T2	−6.687	1.636	< 0.001	[−9.893, −3.481]
Selfcontrol	0.071	0.012	< 0.001	[0.048, 0.095]
Socialanx	−0.009	0.012	0.464	[−0.032, 0.015]
Pandemic Status T1–T2 × Selfcontrol	0.101	0.025	< 0.001	[0.051, 0.150]
Gender	−0.178	0.251	0.479	[−0.670, 0.315]
Age	0	0.026	0.998	[−0.052, 0.052]
Polity	0.097	0.327	0.767	[−0.544, 0.738]
Sibling	−0.073	0.094	0.441	[−0.257, 0.112]
Fam-income	0.024	0.021	0.250	[−0.017, 0.064]
Ind-expenditure	0.066	0.116	0.567	[−0.161, 0.294]
Conditional indirect effect: Pandemic Status T1–T2→Socialanx→Power
Selfcontrol	B	BootSE	BootLLCI	BootULCI
M-1SD	−0.950	0.213	−1.436	−0.622
M	−0.451	0.120	−0.725	−0.264
M+1SD	0.049	0.152	−0.245	0.369
Conditional direct effect: Pandemic Status T1–T2→Power
Selfcontrol	B	SE	LLCI	ULCI
M-1SD	−1.815	0.483	−2.762	−0.868
M	−0.519	0.289	−1.086	0.047
M+1SD	0.776	0.379	0.034	1.518
Index of moderated mediation
	Index	BootSE	BootLLCI	BootULCI
Selfcontrol	0.039	0.011	0.021	0.065

Note: Bootstrap sample size = 5000.

Abbreviations: SE, standard error; B, unstandardized coefficient; CI, confidence interval; LL, lower limit; UL, upper limit.