38 QUARTERLY JOURNAL OF ECONOMICS TABLE II OLS REGRESSION ESTIMATES OF THE EFFECT OF COMPUTER USE ON PAY (DEPENDENT VARIABLE:In (HOURLY WAGE)) October 1984 October 1989 Independent variable (1) (2) (3) (4) (5) (6) Intercept 1.937 0.750 0.928 2.086 0.905 1.094 (0.005)(0.023)(0.026)(0.006) (0.024)(0.026) Uses computer at work(1 yes)0.276 0.170 0.140 0.325 0.188 0.162 (0.010)(0.008) (0.008)(0.009)0.008 (0.008) Years of education 0.069 0.048 0.075 0.055 (0.001)(0.002) (0.002) (0.002) Experience 0.027 0.025 0.027 0.025 (0.001)(0.001) (0.001)(0.001) Experience-squared +100 -0.041-0.040 -0.041 -0.040 (0.002)(0.002) (0.002)(0.002) Black (1 yes) -0.098 -0.066 -0.121-0.092 (0.013)(0.012) (0.013)(0.012) Other race(1 yes) -0.105 -0.079 -0.029-0.015 (0.020)(0.019 (0.020) (0.020) Part-time(1 yes) -0.256 -0.216 -0.221 -0.183 (0.010)(0.010) (0.010)(0.010) Lives in SMSA(1 yes) 0.111 0.105 0.138 0.130 (0.007) (0.007) (0.007)(0.007) Veteran(1 yes) 0.038 0.041 0.025 0.031 (0.011) (0.011) (0.012)(0.011) Female(1 yes) -0.162-0.135 -0.172-0.151 (0.012)(0.012) (0.012)(0.012) Married(1 yes) 0.156 0.129 0.159 0.143 (0.011)0.011) (0.011)(0.011) Married*Female -0.168-0.151 -0.141-0.131 (0.015)(0.015) (0.015)(0.015) Union member(1 yes) 0.181 0.194 0.182 0.189 (0.009)(0.009) (0.010)(0.010) 8 Occupation dummies No No Yes No No Yes R2 0.051 0.446 0.4910.082 0.451 0.486 Notes.Standard errors are shown in parentheses.Sample size is 13,335 for 1984 and 13,379 for 1989. Columns (2).(3).(5),and (6)also include three region dummy variables. models the(raw)differential in hourly pay between workers who use computers on the job and those who do not is 31.8 percent (exp(0.276)-1)in1984,and38.4 percent(exp(0.325)-1)in1989.In columns(2)and(5)several covariates are added to the regression equation,including education,potential experience and its square, gender,and union status.Including these variables reduces the computer premium to 18.5 percent in 1984 and to 20.6 percent inQUARTERLY JOURNAL OF ECONOMICS TABLE I1 OLS REGRESSION ESTIMATES OF THE EFFECT OF COMPUTER USEON PAY (DEPENDENT VARIABLE: In (HOURLY WAGE)) October 1984 October 1989 Independent variable (1) (2) (3) (4) (5) (6) Intercept 1.937 0.750 0.928 2.086 0.905 1.094 (0.005) (0.023) (0.026) (0.006) (0.024) (0.026) Uses computer at work (1= yes) 0.276 0.170 0.140 0.325 0.188 0.162 (0.010) (0.008) (0.008) (0.009) (0.008) (0.008) Years of education - 0.069 0.048 - 0.075 0.055 (0.001) (0.002) (0.002) (0.002) Experience - 0.027 0.025 - 0.027 0.025 (0.001) (0.001) (0.001) (0.001) Experience-squared i 100 - -0.041 -0.040 - -0.041 -0.040 (0.002) (0.002) (0.002) (0.002) Black (1 = yes) - -0.098 -0.066 - -0.121 -0.092 (0.013) (0.012) (0.013) (0.012) Other race (1= yes) - -0.105 -0.079 - -0.029 -0.015 (0.020) (0.019) (0.020) (0.020) Part-time (1= yes) - -0.256 -0.216 - -0.221 -0.183 (0.010) (0.010) (0.010) (0.010) Lives in SMSA (1 = yes) - 0.111 0.105 - 0.138 0.130 (0.007) (0.007) (0.007) (0.007) Veteran (1 = yes) - 0.038 0.041 - 0.025 0.031 (0.011) (0.011) (0.012) (0.011) Female (1= yes) - -0.162 -0.135 - -0.172 -0.151 (0.012) (0.012) (0.012) (0.012) Married (1 = yes) - 0.156 0.129 - 0.159 0.143 (0.011) (0.011) (0.011) (0.011) Married*Female - -0.168 -0.151 - -0.141 -0.131 (0.015) (0.015) (0.015) (0.015) Union member (1= yes) - 0.181 0.194 - 0.182 0.189 (0.009) (0.009) (0.010) (0.010) 8 Occupation dummies No No Yes No No Yes R 0.051 0.446 0.491 0.082 0.451 0.486 Notes. Standard errors are shown m parentheses. Sample srze is 13,335 for 1984 and 13,379 for 1989. Columns (21, (3), (51, and (6)also include three region dummy variables. models the (raw) differential in hourly pay between workers who use computers on the job and those who do not is 31.8 percent (exp(0.276)-1) in 1984, and 38.4 percent (exp(0.325)-1) in 1989. In columns (2) and (5) several covariates are added to the regression equation, including education, potential experience and its square, gender, and union status. Including these variables reduces the computer premium to 18.5 percent in 1984 and to 20.6 percent in