Book excerpt: This study examines laboratory outcomes when there are asymmetric numbers of agents available to bargain over a homogeneous good. When one side of the market is more concentrated than the other side of the market, some agents on one side of the market are unable to trade. For those agents who are matched and the match is confirmed, paired agents proceed into the bargaining rounds. With the data gathered from the market experiments, it is concluded that the concentrated side of the market has more bargaining power; however, the amount of power an agent has is significantly reduced when he makes the initial proposal for a match. By a review of the profits attained from the experiments, market efficiency is significantly lower when the market is asymmetric than when the market is symmetric. Efficiency is significantly different depending on whether the buyer or the seller make the initial proposal for a match.