The purpose of this study is to examine some of the relative merits in applying different accounting techniques to the measurement of wealth, and to the measurement of differences in wealth, such as income. The activities of a commodity trading firm are measured using historical cost FIFO, historical cost LIFO, and current cost accounting. Ijiri and Jaedicke's [1966] reliability measure is used as the basis for comparison of the three techniques, which differ systematically because of their different treatments of the stochastic commodity price. Two basic results emerge. First, any advantage of current cost over historical cost because of the recency of the data used in the current cost measurement may be outweighed because current cost does not take full advantage of past data to average out random errors. Second, the reliability of current cost relative to historical cost can deteriorate as the measurement moves from wealth to income (the difference in wealth) and to force (the difference in income).