Probability theory in fuzzy sample spaces

This paper tries to develop a neat and comprehensive probability theory for sample spaces where the events are fuzzy subsets of The investigations are focussed on the discussion how to equip those sample spaces with suitable -algebras and metrics. In the end we can point out a unified concept of random elements in the sample spaces under consideration which is linked with compatible metrics to express random errors. The result is supported by presenting a strong law of large numbers, a central limit theorem and a Glivenko-Cantelli theorem for these kinds of random elements, formulated simultaneously w.r.t. the selected metrics. As a by-product the line of reasoning, which is followed within the paper, enables us to generalize as well as to bring together already known results and concepts from literature.Acknowledgement. The author would like to thank the participants of the 23rd Linz Seminar on Fuzzy Set Theory for the intensive discussion of the paper. Especially he is indebted to Professors Diamond and Höhle whose remarks have helped to get deeper insights into the subject. Additionally, the author is grateful to one anonymous referee for careful reading and valuable proposals which have led to an improvement of the first draft.This paper was presented at the 23rd Linz Seminar on Fuzzy Set Theory, Linz, Austria, February 5–9, 2002.     

On estimating the mean of the selected normal population under the LINEX loss function

Following Parsian and Farsipour (1999), we consider the problem of estimating the mean of the selected normal population, from two normal populations with unknown means and common known variance, under the LINEX loss function. Some admissibility results for a subclass of equivariant estimators are derived and a sufficient condition for the inadmissibility of an arbitrary equivariant estimator is provided. As a consequence, several of the estimators proposed by Parsian and Farsipour (1999) are shown to be inadmissible and better estimators are obtained. Received January 2001/Revised May 2002     

Productivity and Welfare

Technical change is generally characterized by a rate and biases, both evaluated for given producer prices. This paper examines the potential discrepancy between this rate and the corresponding rate of consumer welfare change as measured by Allais distributable surplus. We postulate a general equilibrium context with various market failures (taxes, quotas, imperfect competition, and “poorly priced” commodities), and use comparative statics to express the rate of welfare change in terms of the rate and biases of the technical change. An elementary simulation model of a taxed economy suggests that the rate of welfare change may differ from the rate of technical change by as much as 50% under plausible circumstances.     

Moral suasion: An alternative tax policy strategy? Evidence from a controlled field experiment in Switzerland

With data gained from a controlled field experiment in Switzerland this paper analyses the effects of moral suasion on the timely paying and the timely filling out of the tax form 2001. Comparisons of different tax filing years and multiple regression estimations have been done using these two factors as dependent variables to check if there is a significant difference between the control group and the treatment group. In February 2002 the treatment group received a letter signed by the communes fiscal commissioner containing normative appeals. Results indicate that moral suasion has hardly any effect on taxpayers compliance behaviour. The strongest effect can be observed for the variable tax payments.Received: February 2003, Accepted: June 2004 JEL Classification: H260, H710BennoTorgler: Special thanks are due to the tax administration of Trimbach, especially to Adolf Müller and Gary Bitterli, who offered me the opportunity to collect the data and assisted the project. Furthermore I acknowledge the financial support of the WWZ-Forum and Swiss National Science Foundation and comments and suggestions from Doris Aebi, René L. Frey, the editor Kai A. Konrad and two anonymous referees.     

Memory recall errors in retrospective surveys: A reverse record check study

This paper reports on a study to compare self-reports during an interview with staff who attended a University health centre in Turkey, with the records of visits to the same health centre over the previous 12 months. Design of the study reflects the effects of importance of the event, duration since the event, frequency of the occurrence of the event, measurement scale of the event, and bounded and unbounded recalling. In order to assess the extent of recall error, responses to retrospective questions on health centre visits are compared with administrative records. Statistical models are proposed for short and long term human memory recall error effects on responses.     

The causal relation between government revenue and spending: Evidence from Egypt and Jordan

In investigating the causal relation between government revenue and spending, our empirical results support the tax-and-spend hypothesis for Egypt and the fiscal synchronization hypothesis for Jordan. Breaking away from these historical trends is essential for both countries to eliminate the budget deficit and therefore ensure the availability of domestic saving for private investment. To cope with unemployment and poverty, continuing privatization is recommended for both countries to improve productivity and efficiency in the domestic economy. Privatization should lead to higher domestic saving and investment and at the same time eliminate the budget deficit by enhancing revenue and curbing spending. (JEL H62, H63)     

Unlocking the potential of advanced manufacturing technologies

This research examines whether investments in advanced manufacturing technologies (AMTs) such as flexible manufacturing systems (FMS), computer aided design (CAD), computer aided manufacturing (CAM), robotics, etc., are more likely to lead to improved performance if they are supported by improvements in the manufacturing infrastructure of the company. This question is evaluated using data gathered from 202 manufacturing plants chosen from industries generally considered to have relatively high investments in technology.Multiple item scales are developed and adapted from sources in the literature to measure investments in technology, infrastructure, and the performance of the plant. Evidence supporting the reliability and validity of these scales is provided. Hierarchical regression is used to analyze the relationship between technology, infrastructure, and performance. The results suggest that there is an important interaction between the adoption of advanced manufacturing technologies and investments in infrastructure. Firms that invest in both AMTs and infrastructure perform better than firms which only invest in one or the other. Separate analyses on sub-samples of firms with the highest and lowest investments in AMTs show that infrastructural investments have a stronger relationship with performance in the high investment group. Thus, the data indicate that infrastructural investments provide a key to unlocking the potential of advanced manufacturing technologies.     

Nash-equilibria in a heterogeneous oligopoly with fuzzy information

We consider a model of an oligopolistic market with heterogeneous firms and products where neither the cost nor the demand functions are common knowledge. Instead, each firm only has some vague ideas about the price strategies adopted by its competitors which is modelled by a fuzzy set. In analogy to the notion of an "equilibrium of actions and beliefs" we define and characterize a generalized Nash-equilibrium and show its existence under general conditions. Furthermore, the impact of the fuzzy information on the equilibrium outcome is analyzed by means of a comparative static analysis within a particular model framework.Received: 28 May 2002, Accepted: 25 December 2002, JEL Classification: D43, D80, L13We wish to thank Bernhard F. Arnold, the editor Murat Sertel , and two anonymous referees for helpful comments. Of course, we are responsible for all remaining errors.     

A note on the determination of A-optimal type block designs under fixed and mixed effects models

In this paper, we consider the problem of estimating a selected set of contrasts between v treatments using a block design consisting of b blocks of size k. Traditionally, the construction of A-optimal block designs for such situations has been carried out assuming a fixed effects model. In this paper, we show that A-optimal designs constructed under a fixed effects model are robust in the sense that these designs have maximal minimal efficiency when considered among all available designs and under all possible mixed effects models. AMS 1991 subject classifications: Primary 62K05; Secondary 62K10