Economics Insights @ CBS

We examine two measures of monthly manufacturing production. The first is the index of industrial production; the second is constructed from the accounting identity that output equals sales plus the change in inventories. We show that the means, variances, and serial correlation coefficients of the log growth rates differ substantially between the two series, and the cross-correlations are in most cases less than 0.4.

This paper utilizes the concept of aggregative consistency defined in Rubinstein and Fishburn [1986], and the FASB's concept of representational faithfulness to evaluate foreign currency translation and accounting for changing prices as embodied in SFAS 70. The paper shows that SFAS 70 produces measurement errors and creates a foreign currency translation adjustment which does not reflect the effects of exchange rate changes. The conditions defined in the paper also facilitate an evaluation of the relative merits of restate/translate and translate/restate.

We consider a single-server queueing system with Poisson arrivals and general service times. While the server is up, it is subject to breakdowns according to a Poisson process. When the server breaks down, we may either repair the server immediately or postpone the repair until some future point in time. The operating costs to the system include customer holding costs, repair costs and running costs. The objective is to find a corrective maintenance policy which minimizes the long-run average operating costs of the system. The problem is formulated as a semi-Markov decision process.