  We introduce a concept called a collective: an interface with a protocol for
aggregating contributions and distributing returns. Through such a protocol,
many members may participate in a mutual endeavor. We present a variety of
real-world examples of collectives to explore the many kinds of things that
members can contribute (such as time, work, ideas, or resources) as well as the
many ways these contributions can be aggregated and returns distributed. In
addition, we illustrate several ways in which new collectives can be
constructed from old, alluding to the fact that all these constructions have a
natural mathematical description within the category of polynomial functors
equipped with a certain monoidal structure.
