  The congestion pricing is an efficient allocation approach to mediate demand
and supply of network resources. Different from the previous pricing using
Affine Marginal Cost (AMC), we focus on studying the game between network
coding and routing flows sharing a single link when users are price
anticipating based on an Average Cost Sharing (ACS) pricing mechanism. We
characterize the worst-case efficiency bounds of the game compared with the
optimal, i.e., the price-of anarchy (POA), which can be low bound 50% with
routing only. When both network coding and routing are applied, the POA can be
as low as 4/9. Therefore, network coding cannot improve the POA significantly
under the ACS. Moreover, for more efficient use of limited resources, it
indicates the sharing users have a higher tendency to choose network coding.
