[Retracted] The Impact of Innovative Industrial Cluster Policy on Regional Innovation: Evidence from a Quasi-Natural Experiment in China

Table 4

The result of robustness test.

Variable	A	B	C	D
treat × post	0.4884 (4.48)	0.5512 (4.83)	0.7592 (4.80)	0.3726 (3.95)
_cons	−4.3794 (−0.77)	−3.2738 (−1.39)	−2.7332 (−1.00)	−5.3238 (−1.99)
Controls	Yes	Yes	Yes	Yes
City FE	Yes	Yes	Yes	Yes
Year FE	Yes	Yes	Yes	Yes
N	833	2926	2660	3192
R^2	0.7902	0.7090	0.6694	0.7537

Notes. t-statistics are in parentheses; , statistical significance at the 5% and 1% levels, respectively; controls represent control variables; _cons represent constant terms; N represents the number of samples.