INFERRING ORDINARY ELASTICITIES FROM CHOICE OR MODE-SPLIT ELASTICITIES

The article details the relationship between travel mode-split and ordinary price elasticities for n transport modes. Mode-split elasticities can be derived from the n X n set of ordinary own-price and cross-price elasticities, but the converse is not true. One ordinary elasticity estimate however makes it possible to infer, directly and indirectly, the n second stage elasticities. Added to the mode-split elasticities, these give the ordinary elasticities. Even when a separate estimate is not available, the system constraints narrow the range of possible values of the ordinary elasticities. (TRRL)