Table 5.

Robustness test: replacement of the core explanatory variable processing method.

	res	res	res1	res2	res3
	(1)	(2)	(3)	(4)	(5)
difi	0.0230***	0.0183**	0.0026**	0.0059***	0.0077**
	(3.85)	(2.24)	(2.32)	(2.93)	(2.34)
_cons	0.0477***	− 0.8994***	− 0.0988***	− 0.2943***	− 0.3533***
	(44.39)	(− 12.16)	(− 11.78)	(− 12.00)	(− 10.91)
Controls	No	Yes	Yes	Yes	Yes
City fixed	Yes	Yes	Yes	Yes	Yes
Year fixed	Yes	Yes	Yes	Yes	Yes
Obs	2870	2870	2870	2870	2870
$R^2$	0.3809	0.4194	0.6181	0.4851	0.3425
F	153.80	103.89	114.24	114.46	127.93
P	0.0000	0.0000	0.0000	0.0000	0.0000

*, **, and ***indicate passing the significance test at 10%, 5%, and 1% levels, respectively.