The arguments of Edwards and Bell for periodical income measurement by use of the entry prices of closing assets are examined critically. Some of the grounds on which their conclusions rest are unobjectionable; but some crucial assumptions are untenable. The purchase prices of goods not yet acquired are necessary in making choices or decisions. But no case was, or can be, established for using entry prices for closing asset valuations in accounts or evaluations of past performance. All like systems fall under the same criticisms.