Re-examination of interest rate sensitivity of commercial bank stock returns using a random coefficient model

This article develops and tests a random coefficient two-index model for commercial bank stock returns which controls for the time-varying interest rate sensitivity caused by a bank's changing maturity profile. Using a sample of 51 actively traded commercial banks, the seemingly unrelated regression results provide evidence that commercial bank stock returns are significantly interest rate sensitive. The effect of interest rate changes on bank stock returns is found to be positively related to the maturity mismatch between the bank's assets and liabilities, when the proxy for interest rate changes and the proxy for maturity mismatch are compatible to each other.This article was written while I was a doctoral student at the University of North Carolina at Chapel Hill. It was presented at the 1989 FMA Annual Meeting in Boston.     

Optimal international hedging in commodity and currency forward markets

This paper derives optimal hedging and production rules for an exporting firm which faces both commodity-price and foreign- exchange-rate uncertainty. The size of the commodity hedge is independent of the properties of the foreign-exchange market. However, the optimal foreign-exchange hedge depends on the commodity hedge and the properties of the commodity forward market. The firm's production decision is independent of its objective function if both forward markets exist, but depends on the consumption beta of the unhedgeable risks in the absence of one or both of the markets.     

The High-Volume Return Premium

The idea that extreme trading activity contains information about the future evolution of stock prices is investigated. We find that stocks experiencing unusually high (low) trading volume over a day or a week tend to appreciate (depreciate) over the course of the following month. We argue that this high-volume return premium is consistent with the idea that shocks in the trading activity of a stock affect its visibility, and in turn the subsequent demand and price for that stock. Return autocorrelations, firm announcements, market risk, and liquidity do not seem to explain our results.     

More or Less Ambition in the Doha Round? Modeling the Development Impact of Recent Proposals

We analyse the impact on developing countries, whose economies depend heavily on agriculture, of a WTO Doha Development Round agreement based on greater or lesser levels of ambition. We present the results of an ambitious versus an unambitious Doha Round outcome, using the MIRAGE model of the global economy, with a special focus on developing countries. Our simulations are based on negotiating proposals from the run-up to the Hong Kong ministerial meeting but not agreed upon in December 2005. We compare those outcomes with the estimated effects of full global trade liberalization. The results for the two Doha scenarios demonstrate the high stakes of this negotiation given the positions of EU, US and the G-20 coalition. A successful round could deliver real gains both globally and for developing countries, but the magnitude of those gains depends on the shape of the agreement. A reform outcome based on the most ambitious components of the negotiating proposals of the US and EU delivers noticeably greater benefits than an unambitious outcome. Developing countries are exposed to very contrasting fortunes. The details matter in the differing proposals, such as the tariff and domestic support reduction formulae, tariff caps, and number of sensitive and special products. Negotiating commitment and diligence are needed in 2006 to avoid a hollow Doha outcome given the technical character of these details.     

AIDS is your business

If your company operates in a developing country, AIDS is your business. While Africa has received the most attention, AIDS is also spreading swiftly in other parts of the world. Russia and Ukraine had the fastest-growing epidemics last year, and many experts believe China and India will suffer the next tidal wave of infection. Why should executives be concerned about AIDS? Because it is destroying the twin rationales of globalization strategy-cheap labor and fast-growing markets--in countries where people are heavily affected by the epidemic. Fortunately, investments in programs that prevent infection and provide treatment for employees who have HIV/AIDS are profitable for many businesses--that is, they lead to savings that outweigh the programs' costs. Due to the long latency period between HIV infection and the onset of AIDS symptoms, a company is not likely to see any of the costs of HIV/AIDS until five to ten years after an employee is infected. But executives can calculate the present value of epidemic-related costs by using the discount rate to weigh each cost according to its expected timing. That allows companies to think about expenses on HIV/AIDS prevention and treatment programs as investments rather than merely as costs. The authors found that the annual cost of AIDS to six corporations in South Africa and Botswana ranged from 0.4% to 5.9% of the wage bill. All six companies would have earned positive returns on their investments if they had provided employees with free treatment for HIV/AIDS in the form of highly active antiretroviral therapy (HAART), according to the mathematical model the authors used. The annual reduction in the AIDS "tax" would have been as much as 40.4%. The authors' conclusion? Fighting AIDS not only helps those infected; it also makes good business sense.     

Outcomes from use of an evidence-based practice guideline

The aim of evidence-based guidelines is primarily to improve patient outcomes without adding to the existing cost of care because both payers and policymakers want to identify health care costs that do not result in benefit to the patient. The purpose of the reported project was to generate a practice guideline for the treatment of uncomplicated acute cystitis in a female population, to determine the extent to which the guideline would be used by providers and to measure the cost and quality of outcomes from its use. A retrospective chart review was used to gather pre-guideline practice and cost data. Measurements included the type, frequency, and duration of antibiotic therapy and the use of urine cultures and both complications and routine followup visits. The implementation of an outpatient practice guideline resulted in a significant change in antibiotic prescribing and a trend toward a change in ordering cultures and clinic followup. There was also a significant decrease in treatment costs.     

Equally-distributed equivalent utility,ex post egalitarianism and utilitarianism

We provide an axiomatization of expected equally-distributed equivalent-utility social welfare functions in the context of Harsanyi?s impartial observer theorem. For this family of social welfare functions, we show what additional axiom is necessary and sufficient for the observer to exhibit aversion to ex post inequality. We also relate this axiomatization to our axiomatization in a companion paper of generalized utilitarian social welfare functions. Given certain richness assumptions, the only social welfare functions that belong to both families are the utilitarian.