The Alliance's Statement on the Co-operative Identity defines a co-operative as "an autonomous association of persons united voluntarily to meet their common economic social and cultural needs through a jointly-owned, democratically-controlled enterprise". It is this definition that marks the difference between the value of a membership share in a co-operative and an equity share in a personally owned and/or joint stock investorowned company. A membership share in a co-operative is invested in the co-operative as common working capital for its business to-operate to meet its members' needs and aspirations and is not a tradable asset. A co-operative membership share is essentially different from an equity share in an investor owned company: the latter is aimed at a generating a return for the investor, including capital gains, and is, generally, tradeable.