The paper considers some differences in the ways that economics and philosophy study equality and egalitarianism in general. First, economics tends to understand a value simply as an ordering over outcomes while philosophy attempts to find a deeper explanation of the ordering in terms of intuitive ideas about the value. Sometimes the supposedly deeper explanation turns out to be insightful, but, in other cases, it is misleading or fails to be explanatory. Second, economists often propose impossibility results intended to show that apparently innocuous ideas about a value can have surprising consequences when they are combined. However, the significance of the results can be difficult to interpret and, sometimes, they do not establish as much as they initially seem to. Third, economists often criticize philosophical work about equality for making misguided assumptions about the possibility of measuring utility or well-being. The paper does not attempt to answer this criticism, but it points out some specific ways in which the scepticism about measurement might be exaggerated.