* PS7.7, using DATA7-5, for the Application in Section 7.8 TIME 1983 12 SAMPLE 1983.01 1990.05 READ(data7-5) PERIOD Q P HS SHC OC L PL * * Model A * OLS Q P HS SHC OC L PL * * Generate the 11 dummies. One for the month of February to December. * MATRIX D=SEAS(89,12) GENR D1=D:1 GENR D2=D:2 GENR D3=D:3 GENR D4=D:4 GENR D5=D:5 GENR D6=D:6 GENR D7=D:7 GENR D8=D:8 GENR D9=D:9 GENR D10=D:10 GENR D11=D:11 GENR D12=D:12 * * Print out D1-D12 to check that these variables were generated correctly. * PRINT PERIOD D1 D2 D3 D4 PRINT PERIOD D5 D6 D7 D8 PRINT PERIOD D9 D10 D11 D12 * * Model B - Leave out variable D1 from estimation to avoid the * Dummy Variable Trap * OLS Q P HS SHC OC L PL D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 * * Model C * SAMPLE 1983.01 1986.06 OLS Q P HS SHC OC D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 * * Omit variables with highest p-values, a few at a time. * Omit D2 D3 * OLS Q P HS SHC OC D4 D5 D6 D7 D8 D9 D10 D11 D12 * * Omit HS * OLS Q P SHC OC D4 D5 D6 D7 D8 D9 D10 D11 D12 * * Omit D8 D9 * OLS Q P SHC OC D4 D5 D6 D7 D10 D11 D12 * * Omit D10 D11 * OLS Q P SHC OC D4 D5 D6 D7 D12 * * Omit D4 * OLS Q P SHC OC D5 D6 D7 D12 * * Omit D5 D7 * OLS Q P SHC OC D6 D12 * * Omit D12 * Model D * OLS Q D6 P SHC OC / COEF=BETA * SAMPLE 1986.07 1990.05 * * The FC command generates forecasts. * DIM QHAT 47 FC Q D6 P SHC OC / LIST PREDICT=QHAT COEF=BETA * * Compute loss in sales and revenues for each month. * GENR QLOSS=QHAT-Q GENR DOLRLOSS=P*QLOSS PRINT Q QHAT QLOSS DOLRLOSS * * Compute sum of losses during the litigation period. * SAMPLE 1986.07 1988.10 * * The MEAN=name option of the STATS command saves the means of the * variables specified in the vector called M1. * STAT QLOSS DOLRLOSS / MEAN=M1 GEN1 TOTQLOSS=28*M1(1) GEN1 TOTDLOSS=28*M1(2) PRINT TOTQLOSS TOTDLOSS * SAMPLE 1988.11 1990.05 * * Compute sum of losses during this period. * STAT QLOSS DOLRLOSS/MEAN=M2 GEN1 QLOSS2=19*M2(1) GEN1 DLOSS2=19*M2(2) PRINT QLOSS2 DLOSS2 * GEN1 SALES=TOTQLOSS+QLOSS2 GEN1 REVENUES=TOTDLOSS+DLOSS2 PRINT SALES REVENUES DELETE / ALL STOP