While antispeciesism is an ethical notion, veganism is behavioral. In this paper, we examine the links between the two. Building on Blackorby and Donaldson (Econ J 102:1345–1369, 1992), we consider a two-species model in which humans consume animals. The level of antispeciesism is conceived as the weight on animals’ welfare in the utilitarian social welfare function. We show that more antispeciesism increases meat consumption if and only if animals’ utility is positive. That is, the critical condition is whether farm animals’ lives are worth living. We then empirically explore this condition using a survey. We find that farm-animal experts and frequent meat eaters are more likely to believe that the lives of farm animals are worth living. We finally discuss some issues in the study of animal welfare in economics and social choice.

反种主义是一种道德观念，而纯素食主义是行为行为。在本文中，我们研究了两者之间的联系。我们以布莱克比和唐纳森（Econ J 102：1345-1369，1992）为基础，考虑了一种人类消费动物的两种物种模型。反种的水平被认为是功利社会福利功能中对动物福利的权重。我们表明，当且仅当动物的效用为正时，更多的抗种种才能增加肉类消耗。也就是说，关键条件是牲畜的生活是否值得生活。然后，我们使用调查经验性地探索这种情况。我们发现，农场动物专家和经常吃肉的人更有可能相信农场动物的生命值得生活。我们最后讨论经济学和社会选择中的动物福利研究中的一些问题。