 As an historical note, Cass never really liked this terminology, preferring instead to think of these models as ones of General Financial Equilibrium (GFE) to emphasize the presence of financial assets and the frictions these introduced.The earliest work on market incompleteness goes back to Arrow in the 1950s, Diamond in the mid-‘60’s and a number of related papers in the finance literature between the late 1950s and early ‘70’s (Geanakoplos  provides an excellent survey of this literature).The canonical GEI model was formulated by Radner in the early 1970s in a paper which also pointed up one of the fundamental puzzles about models with incomplete markets