The food stamp expenditure cap, established in 1977 and subsequently revised, has repeatedly fallen short of program needs at current benefit rates. The desire for fiscal constraint given an unknown participation response to new program provisions, the usefulness of a cap in program management, and the unexpected economic circumstances since 1977 are the subjects of this report. The problems in using a cap created by a rapidly changing economy in 1977-80 are discussed. Finally, a Food Stamp Program Participation model is used to show the suitability of similar models used in original planning of the cap, and the problems created for estimating funding needs during a period of rapidly changing economic parameters.