Postal Service may differ greatly from other postal systems in labor cost, automation, route topography, worksharing, mix of mail by shape, and the percentage of non-delivered mail, etc., we cannot expect the cost estimates furnished by the model to be extremely accurate estimates of particular non-U.S. systems.
Postal systems in different locations face different conditions which may require different cost models.
mnli hypothesis: Postal systems in different locations face different conditions which may require different cost models. premise: Postal Service may differ greatly from other postal systems in labor cost, automation, route topography, worksharing, mix of mail by shape, and the percentage of non-delivered mail, etc., we cannot expect the cost estimates furnished by the model to be extremely accurate estimates of particular non-U.S. systems.