A review of:“DATA ANALYSIS & DECISION MAKING WITH MICROSOFT EXCEL ” By CHRISTIAN S. ALBRIGHT,WAYNE L. WINSTON,CHRISTOPHER ZAPPE Duxbury Press,Pacific Grove,California, 2002, xii + 998 pp. + accompanying CD: ISBN 0-534-38932-5. List: $97·95.

The assumption of a positive marginal tax rate in each period over the life of an investment project does not properly characterize the tax position of a significant number of firms. The paper develops a lower bound on the present value of the tax shield from declining balance depreciation given a reasonable assumption about the stochastic nature of the period by period marginal tax rate. It turns out that the standard textbook formula is a reasonably good approximation of the true present value of the tax shield since our lower bound is very close to the textbook formula.