Designed as a tool for colleges and the State Board for Community Colleges in Maryland to update economic impact data on a regular basis, this manual describes sources of impact information, and how the information can be used in economic equations. Part I of the manual describes how values for short-term economic impacts of community college expenditures can be calculated using data on expenditures of government appropriations and student fees and tuition for salaries, purchase of materials, and capital building improvement. The models, which use linear cash-flow equations, are designed to assess the impacts on the business and government sectors of the economy, and can be used for either a statewide or individual campus study. Part II presents the equations used to determine how much more money a college student will earn than a high school graduate; how much more money college students will earn because of the total investment of the state, local jurisdictions, and the students themselves; and the value of the additional tax revenues generated from the increased earnings. Part III describes the computer programs designed for the study. A bibliography, sample computer print-out, and sample surveys are included. (MB)