| Total sample | Sub-sample 1(horizontal) | Sub-sample 2(vertical) | Sub-sample 3(mixed) |
NumInterlock | 0.704*** (0.000) | 0.554*** (0.001) | 1.327*** (0.000) | 1.161*** (0.000) |
Size | 0.002* (0.067) | 0.033* (0.067) | 0.004* (0.096) | 0.002** (0.042) |
Numdir | 0.026 (0.202) | 0.036 (0.228) | 0.019 (0.696) | −0.017 (0.655) |
PE | 0.001** (0.031) | 0.001* (0.071) | 0.001* (0.082) | −0.001** (0.026) |
ROE | 0.043*** (0.005) | 0.023*** (0.009) | 0.211*** (0.002) | 0.040*** (0.007) |
MRGR | 0.011* (0.093) | 0.001* (0.091) | 0.017* (0.088) | 0.019* (0.081) |
DER | −0.005 (0.555) | −0.001 (0.955) | 0.007 (0.891) | −0.011 (0.495) |
Top1 | −0.002 (0.532) | 0.003 (0.561) | −0.013 (0.157) | −0.005 (0.455) |
Top10 | 0.007** (0.025) | 0.009** (0.037) | 0.005* (0.053) | 0.007** (0.032) |
Beta | 0.245 (0.176) | 0.163 (0.545) | 0.099 (0.824) | 0.753** (0.025) |
α0 | −2.869*** (0.000) | −3.258*** (0.000) | −2.281*** (0.003) | −2.84*** (0.000) |
X2 | 0.299 | 0.271 | 0.469 | 0.410 |