It is pointed out that the OD estimation may be stated as the combination of reconciling information of different types with different error characteristics and from multiple sources, which is known as a mixed estimation in econometrics.

• 并指出可以将OD估计问题陈述为具有不同误差特性、多个来源的不同类型信息的综合性和一致性的结合体 ,此联合估测就是经济计量学的混合估计的问题