【正文】 t exerted by the agents may diminish (Ress, 1985). If more than one agent is required for a task to be acplished then, if collusion can occur, the control of information provided to, and exchanged between, the agents involved needs to be controlled by the principal as it has a bearing on the amount of effort the agents invest into pleting the required task (the greater the effort exerted, the greater the probability of the task being pleted successfully) (Panova and Rangel, 2002). Alternatively, if the agents are in control of the information powerbase the payment for the rent can be maximized – resulting in reduced benefit (per dollar) to the principal.The effort invested by agents could possibly be transferred to other tasks but, given that the greater the effort invested the greater the likelihood of the resultant success of the operation, the principal would prefer more effort to be invested because this means that a greater amount of rent is extracted (where ‘rent’ is the use extracted for a fee). The agent would prefer to acplish the task successfully but with minimum effort. Such is the logical reason for the offering of incentives. As well as being directly relative to the information powerbase, control over the advantage that can be gained in collusion rich environments is also relative to whether or not the multitude of agents that could collude have projects that are symmetrical or asymmetrical. If they are symmetrical then the principal benefits, to a greater extent, if they can somehow prevent the agents from sharing information. Conversely, if the projects are asymmetrical the principal may or may not want the agents to share information – if information sharing and collusion is desirable then the principal will need to offer additional incentives (not exceeding the resultant benefit of the incentive) to the employed agents in order to maintain high levels of effort. Unfortunately for the agents, if the information powerbase lies with the principal then the disutility of effort is likely to be in the favour of the principal also. This costs the agents more, or in other words the principal extracts greater rent for the fee incurred (Panova and Rangel, 2002).When forming contractual relationships with potentially collusive agents there are several options for monitoring behaviour in order for the appropriate rent extraction to be observed. Organisational design is proposed by Vafai (2005) as being an important factor when dealing with an environment where agents could be colluding, identifying that the mon organizational hierarchy exists as principal–supervisor–agent. This is monly used because the supervisor has knowledge or capabilities that the principal does not, or in other words the supervisory monitoring function is more efficient to be delegated rather than acplished by the principal – although the same information could, technically, be available to both. The aforementioned organisational structure, although vastly mon and necessary, may not be the optimal organizational structure in collusive environments because the supervisor may subvert information they do not wish to be conveyed to the principal or could conceal reality by suggesting the monitoring did not reveal the information (difficult to prove). To bat this, or to test the allegiance of the supervisor, the principal could monitor the agents in tandem with the supervisor and pare the results with what the supervisor reports… but then, logically, the whole point of having the supervisor (so effort can be focussed elsewhere) bees irrelevant. The information concealment (the heart of this particular issue) works both ways。 the principal may conceal discoveries that production was greater than expected (or similar rewarding result) and the Agent may wish to conceal a disappointing result. Either way it is the monitoringintermediary (supervising) agent that is subject to the bribery/collusion. It should be clear now that collusive action can be by the principal against agents just like it can be by the agents against the principal. As a solution both the principal and agent need incentives (from each other) to share information for maximum efficiency. Although the weakness of the principalsupervisoragent hierarchy is identified it must be noted that its use allows the principal to extract truth from the agents without having to offer additional rent costs to each individual party. This is referred to as the informationeffect of delegation (Vafai, 2005). Chart 1 illustrates the principalsupervisoragent organisational structure. Vafai offers the concluding statement “the possibility of collusion may set a limit to the size of organizations.” (2005. p1)Chart 1.PrincipalSupervisorAgentAgentAgentAlt