proposed improvement is compared with each al- 

 ternative. 



(iil) Traffic with same commodity and origin-desti- 

 nation, different mode. For commerce shifted to the 

 proposed improvement from other modes, the 

 benefit is any reduction in current and future costs 

 to the producer ar shipper. (See 2.7.2(a)(3)) when 

 movement via the proposed improvement is com- 

 pared with each alternative.) 



(2) Shift of origin benefits. For commerce that 

 originates at a new point because of the proposed 

 improvement, the benefit is the difference between 

 the total cost of producing and transporting the 

 commodity to its destination with and without the 

 plan. 



(3) Shift of destination benefits. For commerce 

 that is destined to a new point because of the pro- 

 posed improvement, the benefit is the difference in 

 net revenues to producers with and without the 

 plan. 



(4) Induced movement benefits. If a commodity 

 or additional quantities of commodity are produced 

 and consumed as a result of a plan, the benefit for 

 each increment of induced production and con- 

 sumption is the difference between the cost of 

 transportation via the proposed improvement and 

 the maximum cost the shipper would be willing to 

 pay. To determine the maximum cost the shipper 

 would be willing to pay, estimate how much of a 

 price increase it would take to induce the producer 

 to increase its output by each increment or how 

 much of price decrease it would take to induce 

 consumers to increase their consumption by each 

 increment. In the absence of data suitable for incre- 

 mental analysis, the expected average transporta- 

 tion costs that could be borne by the induced traffic 

 may be assumed to be half way between the high- 

 est and lowest costs at which any part of the in- 

 duced traffic would move. 



2.7.5 Problems in application. 



(a) fi/fultiport analysis. This procedure calls for a 

 systematic determination of alternative routing pos- 

 sibilities, regional port analyses, and intermodal net- 

 works that may require the use of computer model- 

 ing techniques. The data needed for such a deter- 

 mination are often difficult to obtain; therefore, in- 

 terviews with knowledgeable experts will often have 

 to be relied upon. 



(b) Ultimate origins and destinations. The proce- 

 dure calls for an analysis of full origin-destination 

 costs to determine routings as well as to measure 

 benefits in some instances. Problems will arise in 

 determining the ultimate origins and destinations of 

 commodities and in determining costs. Therefore, 



the analyst should attempt to shorten the analysis 

 to the most relevant cost items. 



(c) Sensitivity analysis. Guidance for addressing 

 risk and uncertainty in the analysis is found in Sup- 

 plement I to Chapter I. The uncertainty in the esti- 

 mates of critical variables should be dealt with. 

 These variables specifically related to deep-draft 

 navigation may be traffic projections, especially for- 

 eign shipments, fleet composition, and cost of com- 

 modity movements. 



(d) Data sources. The following discussion sum- 

 mahzes key data sources including problems in 

 their use: 



(1) Interviews. Collect data not available from 

 secondary sources by personal interviews. (Use 

 only interview forms approved by the Office of 

 Management and Budget.) Display the question- 

 naire used and a summary of responses in the pro- 

 ject report in such a way that individual sources are 

 not disclosed. 



(2) Publications. Data concerning commerce in 

 foreign trade, United States coastal shipping, and 

 activities of U.S. flag vessels in foreign trade, to- 

 gether with limited data concerning the world fleet, 

 are readily available from a number of Federal 

 agencies, trade journals, and port publications. 

 However, data concerning the foreign-flag fleet are 

 often not regularly available in up-to-date form from 

 sources in the United States. Principal governmen- 

 tal sources are the Corps of Engineers, the Mari- 

 time Administration and the Bureau of the Census. 

 For more detailed background on world fleet 

 trends, shipping outlooks, and vessel charactehs- 

 tics, available foreign literature must be carefully 

 analyzed. A few of the available foreign ship regis- 

 ters and literature are listed below to illustrate the 

 type of data available from foreign sources. 



Lloyd's Register of Shipping, London (Annual). 



The Tanker Register, H. B. Clarkson (Annual). 



The Bulk Carrier Register, H. B. Clarkson 

 (Annual). 



Shipping Statistics and Economics (and special 

 reports), H. P. Drewry, Ltd., London (Weekly). 



Fairplay International Shipping Journal (and spe- 

 cial reports), London (Weekly). 



2.7.6 Report and display procedures. 



Clear presentation of study results, as well as 

 documentation of assumptions and steps in the 

 analysis, will facilitate review of the report. The ac- 

 companying tables are suggested. The number of 

 displays will depend on the complexity of the study. 



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