 In contrast to the extensive literature on events and facts, there has been comparatively less discussion of the metaphysics of variables and variable values. When the issue is discussed, many find it congenial to reduce variable values in some way or other to one of the other kinds of entities which have been proposed as token causal relata. In many applications, binary variables (variables which take on two potential values, usually 0 and 1) are used for whether a certain event occurs. Then, questions about what it takes for the variable to take on a value can be translated into questions about what it takes for the relevant event to occur. Hitchcock (2012) suggests that the values of variables be taken to be Lewsian event alterations. (For Lewis [2000], an alteration of an event, e, is a modally fragile event—an event which would not occur, were it ever-so-slightly different—which is not too different from e itself. Some alterations of e will be ways for e to occur, and some will be ways for e to fail to occur, but they are all alterations of e.) An unabridged draft of Hall (2007, see reference for link) proposes that a variable is a family of pairwise incompatible propositions, where each proposition is