Table 3

 Regression results using a full seasonal specification (including an extended sample period)

VariableTotal revenues ($million)Average revenue per machine ($/machine)
EstimateSE*p ValueEstimateSE*p Value
*Newey-West HAC standard errors.
Plaw−6.4871.663<0.001−1567.29348.92<0.001
Time0.6380.117<0.00185.3622.28<0.001
Time2−0.0030.001<0.001−0.1660.1490.269
Machines0.0020.0010.049−2.7280.284<0.001
Income ($trillion)−11.58118.2630.5289493.883535.540.009
Constant30.61826.5630.2521506.595143.920.770
Winter−2.5490.9470.008−614.83242.350.013
Spring2.3260.8290.006892.90235.64<0.001
Summer3.1100.864<0.001908.06228.97<0.001
AR(1)−0.3330.058<0.001−0.3040.064<0.001
n107107
R 2 0.8180.743