The principal-agent model can be more often employed as a conceptual framework for studies in the fields of economics and finance. This article presents real examples in which this theoretical model fits well. It is admitted that the complexity of this type of model can be a barrier to its use. Therefore, it is presented a typical principal-agent model that is simple enough to make it possible to find an analytical solution to the problem. It is shown, relying on the model’s closed-form solution, that moral hazard, in general, lowers efforts by the agent and expected profit for the principal. In fact, it is argued that the consequences of moral hazard would be even worst if no incentive mechanism were in place. Furthermore, it is shown that the greater are the measurement errors, the risk aversion and the cost of effort of the agent; the lower are the effort by the agent and the expected profit for the principal.