Throughput differences between the linear scenario and the CAG scenario are substantial. While the linear scenario reflects well past growth figures, as evidenced by the very high coefficients of determination, CAG scenarios abound in the port traffic forecasting literature. The case of New York underlines that for 2020 the linear growth expectations would place the throughput at 9.6 million TEU, while using the observed CAG of the period 1998-2007, standing at 7.9%, would place throughput at 14.2 million TEU, a difference of 4.6 million TEU. This simple difference in forecasting methodology for a period of 13 years (2007 to 2020) accounts close to the existing volume of the port. The case of Shanghai is absolute and obviously completely unrealistic, as the CAG scenario based on the fast growth figures between 1998 and 2007 (23.9%), would place the port with a throughput in 2020 similar to tha global container port throughput in 2005.