Using an approximate kiefer-weiss solution for testing insect population densities

Summary A sequential testing procedure called 2-SPRT for the meanμ of the negative binomial distribution with known exponentk is presented. For any fixedμ ₀(μ ₁<μ ₀<μ ₂), the 2-SPRT provides an asymptotic solution to the modified Kiefer-Weiss problem. Determination ofμ ₀ such that the test provides an approximate solution to the Kiefer-Weiss problem is described. The behavior of the 2-SPRT and the Sequential Probability Ratio Test is investigated using Monte Carlo methods. The error probabilities and the average sample numbers are compared. All the computations were carried out on the Alabama Supercomputer.     

The effects of mergers on price and output: Two case studies from the airline industry

The literature on industrial organization contains very little direct evidence on the effects of actual mergers. This study estimates the effects of two recent airline mergers approved by the Department of Transportation over the objection of the Department of Justice. The merger of TWA and Ozark appears to have caused a slight increase in fares and a far greater reduction in service on city pairs out of St Louis. The merger of Northwest and Republic appears to have caused a significant increase in fares and a significant reduction in overall service on city pairs out of Minneapolis-St Paul.     

Mortgage-Backed Futures and Options

This paper empirically tests valuation models for the mortgage-backed futures-options contracts that traded on the Chicago Board of Trade (CBOT) from June of 1989 until March of 1992. A simple contingent-claim model is shown to produce call option values on mortgage-backed futures (MBF) contracts that are unbiased estimates of actual futures-options prices. The ability of the MBF contract to hedge positions in current coupon Government National Mortgage Association (GNMA) securities relative to the effectiveness of cross-hedging GNMA positions with T-note and T-bond futures contracts is also examined.     

Net foreign assets of Dutch commercial banks: A comment

Conclusion The article provides a contribution to the discussion on the net foreign assets of the commerical banks, by drawing renewed attention to the possible passivity of the banking sector, which has gained topicality with the striking developments of 1989. Indeed, the banking sector may be considerably more reactive in regards to net foreign assets formation than has been assumed by various authors and in macroeconometric models on the basis of portfolio optimizing behaviour. However, due to the above-mentioned methodological and empirical shortcomings, Bakkers's study certainly does not provide the final answer to this question.     

THE LOCATION OF NONMETROPOLITAN HIGH-TECH INDUSTRIES: A Comparison of Regional Determinants

A study of the location of three classifications of high-tech industries in rural areas was undertaken using ordinary least squares, Tobit, and a two-step estimation procedure suggested by Heckman (1976). The results indicate that the location decision for high tech firms is influenced primarily by the county population, adjacency to an SMSA, and the expenditures on public infrastructure (exclusive of education expenditures). However, location near interstate highways was generally not a significant factor. Results were similar between branch and unit (single ownership) plants. Some differences in signs of orders of magnitude occurred among the estimation procedures. Making a choice between Tobit and Heckman approaches depends upon the goal of the research.     

专门化、多样化和中国地区工业产业增长的关系

本文通过分析中国29个省（除西藏外）的30个工业产业在1988－1997期间的数据。揭示了工业结构和经济增长之间的关系。本文除研究了传统的生产要素的影响外，重点探讨了产业专门化、专业多样化、竞争度和一省发展的初始水平等因素的作用。结果表明，一个产业外部工业环境的多样性和产业内的竞争度有利于产业的增长，但产业专门影响为负。工业结构对于增长的影响在很大程度上依赖于产业的性质及其地理位置。     

The impacts of Hong Kong’s Currency Board reforms on the interbank market

Among the economies with a Currency Board System (CBS), Hong Kong (HK) is probably the one with the largest and most developed financial sector, as well as the highest capital mobility. Hence, studying HK’s CBS is not only crucial to HK, but also important for the understanding of the modern CBS. This paper outlines the major monetary reforms in HK since the late 1980s. The impacts of these reforms and the 1997–1998 Asian Financial Crisis are then examined empirically. We focus on the differentials between the US and HK interbank interest rates. We assume the conditional-mean equation follows an autoregressive process and the conditional-variance equation follows a generalized autoregressive conditional heteroscedasticity process. This model captures the time-varying level and volatility of the differential. In light of the empirical results we provide an assessment of the reforms in HK.     

Optimal Collective Investment in Generic Advertising, Export Market Promotion and Cost-of-Production-Reducing Research

Optimal investment rules are developed for a producer agency investing in domestic-market generic advertising, export market promotion, and cost-of-production-reducing research. These rules are derived assuming either maximization of producers' surplus or social surplus. The form of the optimality rules differs according to which objective is pursued. Fixed producer agency budgets are also allowed by incorporating a constraint limiting total expenditure on the three activities. Addition of such a constraint substantially alters the structure of the optimal investment rules. Differences in these rules highlight the importance of accounting for the financing mechanism when modeling optimal checkoff fund investment decisions. Optimality rules are simulated using data for the Canadian beef sector. Results suggest historic underinvestment in domestic-market generic advertising but overinvestment in export market promotion. Sensitivity of simulation results underscores the difficulty in assessing optimality of historic producer investment in cost-of-production-reducing research.