  We consider the problem of fairly dividing a set of items. Much of the fair
division literature assumes that the items are `goods' i.e., they yield
positive utility for the agents. There is also some work where the items are
`chores' that yield negative utility for the agents. In this paper, we consider
a more general scenario where an agent may have negative or positive utility
for each item. This framework captures, e.g., fair task assignment, where
agents can have both positive and negative utilities for each task. We show
that whereas some of the positive axiomatic and computational results extend to
this more general setting, others do not. We present several new and efficient
algorithms for finding fair allocations in this general setting. We also point
out several gaps in the literature regarding the existence of allocations
satisfying certain fairness and efficiency properties and further study the
complexity of computing such allocations.
