A curtailed test for the shape parameter of the Weibull distribution

Summary A procedure is proposed in this paper for testing the shape parameter, of the Weibull distribution. The test statistic which is based on the extremal quotient, possesses a monotone property which makes it possible for rejection earlier than the last planned observation of the null hypothesis,H ₀: =₀ when the alternative hypothesis isH _a: <₀ and early acceptance ofH ₀ whenH _a: >₀. The test being scale-free, does not require the scale parameter to be known.     

Einige Bemerkungen zur statistischen Messung der Konzentration

Zusammenfassung Nach einer kritischen Analyse der Begriffe „absolute“ und „relative“ Konzentration werden einige Kriterien gegeben, die Ma?zahlen der absoluten oder der relativen Konzentration zu erfüllen haben. Hierauf wird untersucht, inwieweit die gebr?uchlichsten Ma?zahlen der Konzentration (Gini, Herfindahl, Münzner) diese Kriterien erfüllen. Dann wird gezeigt, da? sich eine vonAdam angegebene, sehr allgemeine Klasse von Ma?zahlen als Ma?zahlen der absoluten Konzentration qualifizieren; einige wichtige Spezialf?lle werden genauer untersucht. Im vorletzten Teil der Arbeit werden Ma?zahlen für die Ver?nderung der Konzentration diskutiert und schlie?lich an einem praktischen Beispiel erprobt.

---

Summary After analysing the concepts of “absolute concentration” versus “relative concentration”, some criteria for coefficients of concentration are given to qualify them either as measures for absolute or for relative concentration. On the basis of these criteria, some well-known coefficients (Gini, Herfindahl, Münzner) are examined. Furthermore, it is shown that the measures of “predictivity” as given byAdam can be regarded as coefficients of absolute concentration; some important special cases (one of which the Herfindahl index) are investigated. Finally, measures for the change in concentration are developed and applied to a practical example.

     

On minimum distance estimators for unimodal densities

It is shown that minimum distance estimators for families of unimodal densities are always consistent; the rate of convergence is indicated. An algorithm is proposed for computing the minimum distance estimator for the family of all unimodal densities. References are given to the maximum likelihood method and the kernel method.     

Probenahme vom Band

Ohne Zusammenfassung     

Economie en vooruitgangsidee

Summary The object of this article is the relation between economic science and the idea of progress in western civilization. That relation can clearly be observed in classical economic theory (influenced by the Enlightment) and the modern theory of growth (Golden Age Economics). The author rejects any identification of economic progress with an unlimited increase of GNP. He proposes a link between the idea of economic progress and the divine mandate of stewardship, which implies that the inter-subjective scarcity of non-renewable resources and environmental factors should constantly be taken into account. He concludes with some remarks about economic growth as a goal of economic policy.

---

---

Rede uitgesproken bij de aanvaarding van het ambt van gewoon hoogleraar aan de Vrije Universiteit op 10 maart 1972.     

Economic performance and “frontier” efficiency: A product life-cycle approach

We propose to introduce some economic performance variables of the firms and relate these with the corresponding frontier efficiency measures of 13 industries of the Belgian manufacturing sector in 1978. In order to find groups of similar firms by applying a cluster technique, we assume that this relationship is of a product life cycle nature.In the light of the product life cycle scheme itself and variations of it we can consider the possible explanatory variables of technical inefficiency in each group of firms as sources which intensify or slow-down the economic performance of the firm under consideration. Some cautious characterization of the top and bottom level clusters is formulated and linked to the efficiency issue.This paper was processed by N. R. Adam     

Identification and Measurement of Australian Consumer Sentiment

This article was prepared by Dr L. V. Defris and J. S. McDonnell of the Institute research staff. The authors wish to thank Professor R. F. Henderson and Dr P. J. Sheehan for their helpful comments.