VCS

$a_1$ or $b_1$

$a_2$ or $b_2$

$a_2-b_1$

Panel A: whole sample (Nobs. = 216)

$r_{V_i,t}$

0.0391

(0.0009)**

0.0352

(<0.0001)***

$r_{C_i,t}$

0.0085

(0.1276)

0.0979

(<0.0001)***

0.0266

(0.0067)***

Panel B: Client firm size > vendor firm size (Nobs. = 70)

$r_{V_i,t}$

0.0192

(0.3543)

0.0354

(0.0519)**

$r_{C_i,t}$

−0.0027

(0.7857)

0.0851

(0.0027)***

0.0381

(0.0802)*

Panel C: Client firm and vendor firm belong to the same size quartile (Nobs.=90 )

$r_{V_i,t}$

0.0881

(0.0005)***

0.0366

(0.0004)***

$r_{C_i,t}$

−0.0053

(0.4447)

0.1387

(<0.0001)***

0.0423

(0.0011)***

Panel D: Client firm size < vendor firm size (Nobs. = 56)

$r_{V_i,t}$

0.0472

(0.0154)**

0.0235

(0.0024)***

$r_{C_i,t}$

0.0354

(0.0007)***

0.0343

(0.2018)

−0.0114

(0.3992)