According to the Coase theorem when transaction costs are sufficiently low then bargaining will lead to an efficient outcomeregardless of the allocation of property. There ishigh degree of Similarity between lawand ethics and when transaction costs are sufficiently low then ethics, aswell aslaw,doesnot havean impact onthe efficiency of society. This articlestudies the role of ethics to reach the maximum efficiency and shows hownomoralobligationto reduceeconomic efficiency and ultimately reducethewealthof society. Sufficientlylow transaction costs assumption is dependent on the ethicsand there is no maximum efficiency if there is no moralobligation.