This paper analyzes the incentives to trade and the validity of the law of
one price in three strategic market games with multiple trading posts. In b
ilateral oligopolies, where traders have corner endowments in one commodity
, all agents participate in all the markets. The law of one price holds in
bilateral oligopolies and in the buy-or-sell market game, where equilibrium
strategies are locally unique, When traders can simultaneously buy and sel
l on every market, the law of one price fails and the set of equilibrium pr
ices generically has the same dimension as the number of active markets. (C
) 2001 Academic Press.