English: Effective altruism has focused on moral efficiency, i.e. the ratio of the resources used (money, time ...) to the moral benefit achieved, in addition to the extent of our moral commitment, and has called for the maximum efficiency of moral commitment. This raises two questions, among others, which are the subject of this paper: 1. How does one calculate moral efficiency? 2. Is maximum moral efficiency the right moral decision-making criterion? In the article, efficiency calculations of donations for two (...) charitable projects are presented in detail (question 1): distribution of mosquito nets in malaria areas in sub-Saharan Africa and maintenance of a children's village in Guatemala. The result is that the children's village project is clearly less efficient. Should it therefore be abandoned, although it seems to be a very useful project (question 2)? (shrink)