Envy of others' material possessions is a potent motivator of consumerism. This makes it a prudentially and morally hazardous emotional response. After outlining these hazards, I present an analysis of the emotion of envy. Envy, I argue, presents things in the following way: the envier lacks some good that her rival possesses; this difference between them is bad for the envier; this difference reflects poorly on the envier's worth; and this difference is undeserved. I then discuss the conditions under which these presentations can be satisfied by differences in material possessions. My conclusion is that no difference in material possessions can simultaneously be all the ways envy presents it as being. Consequently, economic envy is systematically irrational: it is never a warranted response to the distribution of material wealth. Recognising this bolsters the prudential and moral case for reducing the degree to which we feel it and for resisting the inclinations it gives rise to when we do.