Table 2: Estimates of fixed effects models of productivity using Cobb-Douglas function.

Fixed effects models
Model 1Model 2Model 3Model 4

Real capital0.1781*** (0.0269)0.1701*** (0.0268)0.1652*** (0.0268)0.1612*** (0.0269)
Employment0.8959*** (0.0231)0.9095*** (0.0233)0.9077*** (0.0231)0.9027*** (0.0233)
Year0.0134*** (0.0007)0.0100*** (0.0010)0.0131*** (0.0008)0.0169*** (0.0026)
Years of schooling0.6583*** (0.1697)−0.8463 (0.5562)
Relative schooling0.2315*** (0.0507)0.4728** (0.1665)
Experience0.0060 (0.0566)−0.0382 (0.0533)−0.1033 (0.0683)
Female (%)0.0034 (0.0053)0.0032 (0.0053)0.0023 (0.0053)
Black (%)−0.0001 (0.0016)−0.0001 (0.0016)−0.0001 (0.0016)
Hispanic (%)0.0006 (0.0012)0.0007 (0.0012)0.0006 (0.0012)
Other race (%)−0.0001 (0.0008)−0.0002 (0.0008)−0.0002 (0.0008)
Metro (%)0.0758** (0.0282)0.0705* (0.0282)0.0680* (0.0282)
Constant3.3039*** (0.1996)1.7077** (0.5518) 3.7017*** (0.2583)6.2405*** (1.6882)
R-squared.988.989.989.989
Sigma u .4023.3735.3733.3777
Sigma e .1034.1025.1022.1022
Bic−2193.908−2174.008−2180.135−2175.471
N 1262126212621262

The year variable is linear and increments by one annually beginning in 1979.
* P < 0.05, **P < 0.01, ***P < 0.001 (two tailed tests).