This paper introduces an agent-based model of a passenger
railway line. The model is used for comparing the welfare of
the railway market under unregulated duopoly and monopoly with
maximum-price regulation. In the model, the railway operators
gradually adjust passenger fares and eliminate train departures
until the market reaches steady state. The paper analyses the
steady-state data generated using two sets of parameter values.
It finds that for most maximum-price levels, including the
price that would be chosen by an unregulated monopoly, the
total welfare in the monopolistic market is significantly lower
compared to the duopoly market. However, there are some levels
of maximum price which produce similar or even higher welfare
than the duopoly market. The paper suggests that if correctly
implemented, a simple maximum-price regulation may generate
welfare outcomes comparable to competition.