For passengers to reach the final destination of the trip it is often necessary to make use of the transport services provided by several firms. When these transport services follow in a natural transport chain they are characterized as complementarities and the firms providing the services can,...

The paper first briefly reviews the extent to which profit maximising transport firms with identical cost functions and producing identical transport services pass-on output taxes to transport users under perfect competition, under different forms of imperfect competition and when they act as...