177 NTU Management Review Vol. 31 No. 2 Aug. 2021 Panel B.2 DID Regression Results for Adjusted Patent Citations in the Inter-industry Analysis: High R&D Intensity Firms One Matched Firm Two Matched Firms Three Matched Firms Four Matched Firms (1) (2) (1) (2) (1) (2) (1) (2) Aftert 0.0038 0.0054 -0.0954* -0.0915* -0.046 -0.0401 -0.1004** -0.0932** (0.9344) (0.9097) (0.0711) (0.0811) (0.2955) (0.3613) (0.0114) (0.0183) Treatmenti -0.0734* -0.0779* -0.1178* -0.1163* 0.0115 0.0152 -0.0373 -0.0338 (0.0787) (0.0878) (0.0528) (0.0685) (0.8424) (0.8069) (0.5114) (0.5745) Aftert × Treatmenti 0.0187 0.0196 0.0979 0.0698 0.0350 -0.0030 0.0873 0.0378 (0.7497) (0.7517) (0.2290) (0.4027) (0.6501) (0.9706) (0.2593) (0.6360) LN (1+NetSalest-1) 0.0076* 0.0074 0.0195*** 0.0196*** 0.0358*** 0.0361*** 0.0322*** 0.0328*** (0.0876) (0.1341) (0.0021) (0.0038) (0.0000) (0.0000) (0.0000) (0.0000) RDt-1 0.0015** 0.0013** 0.0006 0.0003 0.0008 0.0005 0.0016** 0.0013* (0.0156) (0.0486) (0.4083) (0.6658) (0.2572) (0.5157) (0.0135) (0.0524) Tobin’s Qt-1 0.0002 0.0081* 0.0102** 0.0142*** (0.9483) (0.0696) (0.0216) (0.0015) Observations 598 558 986 929 1,368 1,290 1,754 1,663 Adjusted R2 0.0638 0.0696 0.0729 0.081 0.1151 0.1256 0.0884 0.0984 Note: This table presents the panel regression results of subsamples divided by different firm sizes, including small and large firms in the inter-industry analysis. Panels A.1 and A.2 show the regression results that explain the R&D investment for low and high R&D intensity firms, respectively. Panels B.1 and B.2 show the regression results that explain the adjusted patent citations for these two subsamples. The dependent variable in Panels B.1 and B.2 is LN (1+adjusted patent citation). The regression is shown in equation (1) of Section 3.3.4. Aftert = 1 if the firm is in the approval year or after approval year and 0 otherwise; Treatmenti = 1 if the firm is in the treated group and 0 otherwise. The treated firms are approved biopharmaceutical firms and control firms are high-tech firms. The definitions of the variables are presented in Appendix Table A1. Numbers in the parentheses are p-values. ***,**, and * denote significance at the 1%, 5%, and 10% levels, respectively. 5. Conclusion This study investigates the impact of the Biopharmaceutical Act on firm innovation. To overcome the endogeneity problem, we first use the PSM approach to identify suitable control firms and then adopt the DID approach to examine how the innovation activities of approved biopharmaceutical firms, relative to control firms, respond to the exogenous Table 10 DID Regression Result of Inter-industry: Subsample Analysis for Different R&D Intensity Level (cont.)
RkJQdWJsaXNoZXIy ODg3MDU=