PROPENSITIES TO SHIP MANUFACTURES BY RAIL WITHIN FOUR U.S. TRAFFIC FLOWS (ABRIDGMENT)

The use of a freight transportation service at two levels of geographic aggregation, represented by nonoverlapping component traffic flows and the aggregate that combines them, is modeled. The basic aim is estimators of demand parameters. Propensity is used to denote the nonrandom part of the actual percentage of goods shipped via the specified service. The general approach is by three hypotheses: The first states that the expected value of use in the aggregate is a weighted average of expected use in the components. The second states that the expected use in each component equals expected aggregate use plus a constant. The third states that all of the random variables describing service use have the same form whether aggregate or component. An illustrative study of rail shipments by manufacturers using four component traffic flows is included. It is noted that greater commodity detail and the inclusion of at least a relative price are required for a conclusive empirical study.

Media Info

  • Media Type: Print
  • Pagination: p 62
  • Monograph Title: Forecasting passenger and freight travel
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00176461
  • Record Type: Publication
  • ISBN: 0309026644
  • Files: TRIS, TRB
  • Created Date: Jun 14 1978 12:00AM