This paper investigates the intradaily operational efficiency of the U
S foreign exchange market by conducting computer simulation experiment
s with market structure (the numbers of market-makers, brokers and cus
tomers). The results indicate significant operational inefficiencies w
hich can be explained by temporary inventory imbalances inherent in a
decentralized market. The results also suggest that much of this ineff
iciency could be alleviated through a centralization of price informat
ion.