Kingdon (1995, 116) described the policy stream as consisting of a "policy primordial soup" in which multiple ideas are just "floating" around,
waiting to be scooped up by prominent government actors.
The primordial soup is akin to the garbage can put forth
by Cohen, March, and Olsen (1972).
Both problems and solutions get dumped into the same policy can, resulting in an unpredictable process of policy change.