We propose a general approximation method for the determination of optimal trading strategies in markets with proportional transaction costs, with a polynomial approximation of the residual value function. The method is exemplified by several problems, from optimally tracking benchmarks and...

For quite a long time, network industries used to be regarded as (natural) monopolies. This was due to these industries having some special characteristics. Network externalities and economies of scale in particular justified the (natural) monopoly thesis. Recently, however, a trend towards...