5.1 Introduction5.2 Translog Linear Models Based on (X1,X2,Y1)5.3 Translog Linear Models Based on (X1,X2,Y2)5.4 Forecast Models Using Original (X1,X2,Y)5.5 Alternative Forecast Models Using Original (X1,X2,Y)5.6 Forecasting Models with Trends Using Original (X1,X2,Y)5.7 Application of VAR Models Based on (X1t,X2t,Y1t)5.8 Applications of the Object “System”5.9 Models Presenting Causal Relationships Y1,Y2, and Y35.10 Extended Models5.11 Special Notes and Comments