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.     

Nonparametric estimation of distribution functions

Summary Using Silverman and Young’s (1987) idea of rescaling a rescaled smoothed empirical distribution function is defined and investigated when the smoothing parameter depends on the data. The rescaled smoothed estimator is shown to be often better than the commonly used ordinary smoothed estimator.     

Option Trading and the Intervalling Effect Bias in Beta

Prior studies show that the beta coefficient of a security changes systematically as the length of measurement interval is varied. This phenomenon, which is called the intervalling effect bias in beta, has been attributed to the friction in the trading system that causes the delays in the price-adjustment process. This study shows that option listing is associated with a decline in the beta intervalling effect bias. The decline is most pronounced for small firms. We also find that our sample firms grow significantly after option listing. Since prior research indicates that market value is a major determinant of the magnitude of the intervalling effect, we re-examine our results using a subsample that controls for market value. The results indicate that the decline in the beta bias from the pre-listing to post-listing period is still prevalent after we control for the change in firm size. Overall, the evidence is consistent with the notion that option trading reduces the delays in the price-adjustment process, which in turn reduces the intervalling effect bias in beta.     

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.     

Two-Part Trade Policy under Imperfect Competition

In this paper we consider the potential gain of a government pursuing a two-part trade policy: an import license for entry, along with a per-unit tariff on imports. The model is a two-stage game of complete but imperfect information. In the first stage, the domestic government sets trade policy, while in the second stage the home and foreign producers behave as Cournot competitors. The paper demonstrates that the optimal trade policy depends upon the number of firms, the degree of heterogeneity in cost functions, and the degree of convexity in cost functions.     

The Structure of Protection in Indonesia in 1989 1

Around the mid-1980s, Indonesia's protectionist regime supported an industrial structure in which industries were mainly oriented towards producing for the domestic market. Since then, trade policies have shifted to a more outward-looking strategy, stimulating the growth and diversification of non-oil manufactured exports. This paper attempts to quantify the nominal and effective rates of protection resulting from trade policies at the end of the 1980s. After an introduction in which the 1989 trade policies are discussed, estimates of nominal and effective rates of protection are presented. It is shown that though the level of protection has declined since 1987, it still varies widely across economic sectors. Furthermore, despite the more open trade strategy, the paper's findings show that the trade regime remains biased against exports. Finally, by examining some trade policy issues, the paper presents further ways of rationalising the structure of protection in Indonesia's industrial sector.     

REBALANCING EC CEREALS PROTECTION AND THE GATT URUGUAY ROUND

This paper considers the proposals put forward by the EC at the GATT Uruguay Round in December 1990. The EC's objective of rebalancing the Common Agricultural Policy in the context of a partial liberalisation of agricultural support on the world cereals market is assessed, as is the choice of base year from which liberalisation would have been initiated. The US's proposal for more significant reduction in agricultural support is also considered. The results show that the EC would not necessarily have benefited from rebalancing, since the effects would have depended on the choice of base period. For example, with 1986 (1988) as the base year, net welfare changes would have been 20 (50) percent higher (lower) with rebalancing, relative to the case without. Not surprisingly, the more substantial liberalisation proposed by the US would have resulted in greater net welfare gains even if rebalancing was conceded by the US.