Intercept 1156.86 983.17 1865.60 693.85 (20.85)*** (113.66)*** (176.73)*** (126.72)*** Airport dummies NO NO NO NO Year dummies YES YES YES YES R2 0.05 0.06 0.08 0.19 25.59*** 21.90*** 16.88*** 8.04*** Test F (joint sig.) 10472 7161 4279 2805 Number observations Note 1: Standard errors in parenthesis (robust to heterocedasticity) Note 2: Statistical significance at 1% (***), 5% (**), 10% (*) Note 3: We use one lag of concentration variables (HHI_route, HHI_airport)
Intercept 1156.86 (20.85)*** 983.17 (113.66)*** 1865.60 (176.73)*** 693.85 (126.72)*** Airport dummies NO NO NO NO Year dummies YES YES YES YES R2 Test F (joint sig.) Number observations 0.05 25.59*** 10472 0.06 21.90*** 7161 0.08 16.88*** 4279 0.19 8.04*** 2805 Note 1: Standard errors in parenthesis (robust to heterocedasticity) Note 2: Statistical significance at 1% (***), 5% (**), 10% (*) Note 3: We use one lag of concentration variables (HHI_route, HHI_airport)