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Table 6 Robustness analysis

From: Research on interaction of innovation spillovers in the AI, Fin-Tech, and IoT industries: considering structural changes accelerated by COVID-19

Depend Variable

Model 6

Model 7

Model 8

Model 9

Model 10

\(({R}_{i,t}-{R}_{f,t})\)

Coefficient

t-statistic

Coefficient

t-statistic

Coefficient

t-statistic

Coefficient

t-statistic

Coefficient

t-statistic

Intercept

 − 0.01913***

 − 2.767963

 − 0.00820***

 − 8.367746

 − 0.07094***

 − 7.366044

 − 0.00250***

 − 3.723975

 − 0.070238

 − 1.172472

(\({R}_{m}-{R}_{f}\))

1.22E − 05***

11.86222

0.85474***

35.03743

1.32E − 06

0.265783

0.86485***

35.46774

1.96E − 06

0.523152

BMR

 − 0.11250***

 − 18.88183

0.00017

1.500401

 − 0.03253***

 − 10.60821

 − 7.80E − 05

 − 0.684450

 − 0.032641

 − 0.880640

Asset

3.09E − 06***

3.659897

0.00065***

7.993936

 − 4.48E − 06

 − 0.532548

    

Size

      

5.65E − 09

0.466802

 − 0.000282

 − 0.066990

D

  

0.00763***

5.713188

0.18520***

4.113677

0.00124

1.621585

0.105553

1.076105

\({\sigma }_{i,AI,t-1}^{2}\)

8.90E − 13***

4.252773

 − 1.15E − 07***

 − 3.239342

5.08834***

2.238173

 − 1.14E − 07***

 − 3.209619

2.13E − 07

0.816159

\({\sigma }_{i,Fin-Tech,t-1}^{2}\)

1.38E − 13**

2.097997

6.51E − 08***

3.796569

 − 5.08850***

 − 2.237765

6.74E − 08***

3.933979

 − 5.92E − 06

 − 0.816184

D*(\({R}_{m}-{R}_{f}\))

  

0.026691

0.916722

1.00311**

380.3264

0.01470

0.505392

1.002839

440.6452

D*BMR

  

 − 0.000456***

 − 3.358283

0.02790**

5.500631

 − 0.00017

 − 1.372978

0.031740

0.885858

D*Asset

  

 − 0.000701***

 − 5.542301

 − 0.00191

 − 0.470347

8.75E − 09

0.712404

0.007333

0.762140

D*\(({\sigma }_{i,AI,t-1}^{2}\))

  

1.15E − 07***

3.239344

1.49E − 06

0.459562

1.14E − 07***

3.209628

1.34E − 06**

2.227196

D*(\({\sigma }_{i,Fin-Tech,t-1}^{2}\))

  

 − 6.51E − 08***

 − 3.796561

6.50E − 06**

2.526280

 − 6.74E − 08***

 − 3.933967

6.82E − 06

0.908963

\({\sigma }_{i,AI,t}^{2}\)

      

 − 5.38E − 13

 − 0.683252

1.52E − 07

0.778654

\({\sigma }_{i,Fin-Tech}^{2}\)

      

 − 3.05E − 14

 − 0.065451

 − 4.22E − 06

 − 0.778672

N

58,589

46,690

11,899

46,690

11,899

Adj. R

0.046774

0.101584

0.969655

0.101229

0.969712

F − statistic

575.9601***

482.8721***

322.6276***

407.1542***

322.7338***

  1. Robustness models: \({R}_{i,t}-{R}_{f,t}={{\alpha }_{0s{\left(ns\right)}_{pre}-covid}+(\alpha }_{0s{\left(ns\right)}_{covid}}-{\alpha }_{0s{\left(ns\right)}_{pre}-covid})D+{\beta }_{1s{\left(ns\right)}_{pre}-covid}{(R}_{m,t}-{R}_{f,t})+({\beta }_{1s{\left(ns\right)}_{covid}}-{\beta }_{1s{\left(ns\right)}_{pre}-covid})D{(R}_{m,t}-{R}_{f,t})+{\beta }_{2s{\left(ns\right)}_{pre}-covid}ln{\left(ASSET, SIZE\right)}_{i,t}+({\beta }_{2s{\left(ns\right)}_{covidS}}-{\beta }_{2s{\left(ns\right)}_{pre}-covid})Dln{\left(SIZE\right)}_{i,t}+{\beta }_{3s{\left(ns\right)}_{pre}-covid}{\left(BMR\right)}_{i,t}+({\beta }_{3s{\left(ns\right)}_{covid}}-{\beta }_{3s{\left(ns\right)}_{pre}-covid}){D\left(BMR\right)}_{i,t}+{\beta }_{4s{\left(ns\right)}_{pre}-covid}{\left({\sigma }_{i,AI}^{2}\right)}_{t-1}+({\beta }_{4s{\left(ns\right)}_{covid}}-{\beta }_{4s{\left(ns\right)}_{pre}-covid})D{\left({\sigma }_{i,AI}^{2}\right)}_{t-1}+{\beta }_{5s{\left(ns\right)}_{pre}-covid}{\left({\sigma }_{i,Fin-Tech}^{2}\right)}_{t-1}+({\beta }_{5s{\left(ns\right)}_{covid}}-{\beta }_{5s{\left(ns\right)}_{pre}-covid})D{\left({\sigma }_{i,Fin-Tech}^{2}\right)}_{t-1}+{\beta }_{6s(ns)}\left({\sigma }_{i,AI,t}^{2}\right)+{\beta }_{7s(ns)}\left({\sigma }_{i,Fin-Tech,t}^{2}\right)+{\varepsilon }_{i,t}\), \({\varepsilon }_{i,t}\)=\({\mu }_{i}+{\lambda }_{i}+{\nu }_{i,t}\) (p < 0.01); Model 6 examines H1, Model 7 and 9 examine H2, and Model 8 and 10 examine H3; each model lists the coefficients and t-values of period random effects; *** (P < 0.01), and ** (P < 0.05) are statistically significant; the significance of the main variables is shown in bold