This study analyzes the agency problem of conflicts of interest arising from differences in risk aversion between principals and agents in the context of investment scale decisions. When the expected utilities of both the principal and the agent are expressed as linear functions of expected returns and variance as a measure of risk, the study demonstrates that agency costs do not exist if the agent's compensation function is appropriately structured with a fixed salary and a bonus consisting of a share of returns. Regardless of whether multiple agents are organized in a hierarchical structure, a team structure, or a subcontracting structure, optimal investment scale decisions can be achieved. Therefore, in terms of risk sharing, different organizational structures achieve the same effect. This study demonstrates that when agents make investment decisions that principals deem inappropriate, this is not due to differences in risk preferences but rather due to compensation structures that inappropriately allocate risk.