Table 5.

Cumulative abnormal returns in the materials industry during different event window periods.

Scenario	Variables	Window	Statistical analysis
			Mean	Std. dev.	t-test	Wilcoxon
Before the rising value-added tax, 2019 (VAT = 5 %)	$TA$	[-7,+7]	14.280	47.040	2.2701	1.4616
	$SE$	[-7,+7]	7.170	24.770	3.0151∗∗	2.2965
	$TLSE$	[-7,+7]	14.280	47.040	8.8729	5.0919
	$TI$	[-7,+7]	0.200	0.670	0.0623	0.0255
	$TR$	[-7,+7]	0.210	0.650	0.0467	0.1144∗∗
	$TE$	[-7,+7]	0.190	0.740	0.0252	0.0249∗∗
	$NI$	[-7,+7]	0.0087	0.140	0.0037	0.0042
	$COA$	[-7,+7]	0.041	0.500	0.0135	0.0397
	$CIA$	[-7,+7]	0.390	1.410	0.3874	0.1695
	$CFA$	[-7,+7]	−0.920	3.170	−0.7669∗∗∗	−0.4936∗∗∗
	$CEP$	[-7,+7]	1.310	5.500	1.2892	0.9199
After the rising value-added tax, 2020 (VAT = 15 %)	$TA$	[-7,+7]	13.490	44.080	1.8493∗∗∗	0.9813
	$SE$	[-7,+7]	6.930	24.260	0.6219	0.3800∗
	$TLSE$	[-7,+7]	13.490	44.080	7.4654	6.7692
	$TI$	[-7,+7]	0.240	0.950	0.0311∗	0.0392∗∗
	$TR$	[-7,+7]	0.270	1.060	0.0637	0.0554
	$TE$	[-7,+7]	0.170	0.840	0.1285	0.0382
	$NI$	[-7,+7]	0.058	0.170	0.0300∗∗∗	0.01892
	$COA$	[-7,+7]	0.026	0.250	0.0260	0.0193∗∗∗
	$CIA$	[-7,+7]	−0.039	0.300	−0.0374	−0.0186
	$CFA$	[-7,+7]	−0.610	2.410	−0.5337	−2.0618
	$CEP$	[-7,+7]	1.070	4.430	0.7811	3.9055

∗∗∗, ∗∗, ∗ represent 1, 5, and 10 % significance levels, respectively.