The following is mostly intended as background for a possible post (or posts) on quantity effects of a job guarantee in which the standard income-expenditure model is taken as a base. It is desirable to work from as simple a starting point as possible as the exercise can complicate pretty quickly. To minimize unnecessary complications, the base model will be presented in highly abbreviated form. This will not cause anything important to be lost because it is always possible to switch back to the more detailed version of the model when desired. The abbreviation has already appeared here and there in earlier posts, but to avert possible confusion it seems advisable to spell out exactly how it corresponds to the more familiar version of the model.