Why is the trade pattern different from that predicted by the classical model?

The reasons for the difference between the trade pattern and the trade pattern predicted by the classical model;

1, this classical model is only the corresponding specialized or idealized state, which is far from this reality, but it is impossible to deal with it completely according to this requirement at present.

This related trade pattern must be adjusted according to our own situation, including the exchange of funds, the circulation of goods and the management of personnel, and we must have our own set of management methods.