Panels A: Summary statistics
	Before the COVID-19 outbreak					During the COVID-19 pandemic
Variable	Mean	St.Dev.	Min	Max	N	Mean	St.Dev.	Min	Max	N
NBV_S	16.064	15.547	-19.998	77.718	233	28.032	24.012	-12.69	95.93	59
NBV_Retail	16.316	18.744	-30.989	80.807	233	30.873	30.866	-22.32	118.6	59
RetZZQZ	0.001	0.013	-0.067	0.056	233	-0.001	0.020	-0.0820	0.0360	59
Panels B: Results of Augmented Dickey–Fuller unit root tests
	Before the COVID-19 outbreak					During the COVID-19 pandemic
NBV_S	-11.879***					-7.955***
NBV_Retail	-11.911***					-8.396***
RetZZQZ	-14.666***					-7.583***