摘要：The economic efficiency of an action differs from inefficiency not only due to the multitude of positive effects compared to the expenses, but also due to the report that exists between the positive economic effects and the negative ones. Although the positive effects are also useful, between their positive and useful character there is not a linear relation. The link between the volume of the positive effects (such as those linked to the production, from others can derive) and their total utility is complex, which imposes an analysis of the intervals of the effects variations
