Solving for Q yields:


 (-= ( + P
 b d

 The elasticity of demand for transportation (ET) is:

 -1 PT
 (8) ET 1 1 Q
 (+-- + )
 b d

 From (1) and (2) and using (3) we may derive the following:

 EDQ
 (9) b = and
 PQ

 ESQ
 (10) d =--
 FOB

where
 ED = elasticity of demand for the commodity.

 ES = elasticity of supply for the commodity.


Substituting (9) and (10) into (8) yields


 EDES PT
 (11) E = (P E-S FBED)



Recalling that PFOB PQ PT (11) may be rewritten as:


 EDE PT
 (12) E = ( PT )
 T P P D
 ES (1 --) ED
 Q
or

 ES PT
 (12a) ET= (-- ) ED
 E ( --) E
 Q