预拌自密实混凝土应用性能的控制

自密实混凝土(SVB)特点主要体现在其新拌混凝土的特别的性能。然而自密实混凝土这些特性是通过质量稳定的最优化的原材料以及制造过程达到的。在实际应用时,作为预拌自密实混凝土浇筑时,其必须显示出所需要的新拌混凝土特性。在混合物混合结束与浇筑开始之间的间隔时间总计可能超过90min,在这较长时间间隔情况下,与在预制工厂应用相比,要求考虑时间和温度对自密实混凝土(SVB)的实用特性变化的影响。掌握粉体材料应用、含水量和增塑剂作用原理以及其相互影响方面的足够的知识是必要的。混凝土原材料和混凝土构成对混凝土流变性能、混凝土硬化性能和施工性能的影响由试验室试验确定。在对预拌混凝土相同原材料和相同配合比的监督检查应根据在结合实际情况下进行,混凝土的可否运送由试验室的结果确定。所有被监督检查的混凝土应符合客户订货确定的硬化混凝土性能要求。     

Information Asymmetries as Antecedents of Opportunism in Buyer-Supplier Relationships: Testing Principal-Agent Theory

ABSTRACT

Purpose: A severe problem in supplier selection refers to moral hazard: suppliers not behaving in the expected way once contracted. Principal-agent theory could provide insights on how to reduce this problem. Because buyer–supplier relationships can be interpreted as principal-agent situations, the application of agency theory should facilitate improved supplier selection. Although theoretically compelling, empirical tests verifying this assumption are not prevalent. Regarding the advancement of theory, this paper tests whether both ex ante and ex post information asymmetries influence moral hazard. In particular, in the context of a globalizing economy with a subsequent increase in information asymmetries as a problem in supplier selection, this conceptual approach may be contributive.

Design/methodology/approach: The authors use a set of 87 buyer–supplier relationships to conduct a test, applying a partial least squares model with latent variables. A particularity of the data set is that it contains information on ongoing as well as on discontinued relationships.

Findings: The analysis indicated that both ex ante information asymmetries (operationalized by a reputation variable) and ex post asymmetries (operationalized by a monitoring variable) have shown to be significant and strong antecedents explaining the occurrence of moral hazard. Interestingly, and opposed to the common assumption, the length of a relationship and the amount of direct meetings have not revealed any explanatory significance. Buyer dependency hardly showed influence on supplier opportunism.

Research limitations/implications: Data were collected from a multitude of buyer–supplier relationships from a single firm in the chemical-pharmaceutical industry. Generalizations to other industries still need to be tested. Socially desirable answering behavior cannot fully be excluded because relationship discontinuation is not a desirable situation. In terms of theory implications, this research adds to the notion that both hidden action and hidden intention can lead to moral hazard.

Practical implications: An agency-based analysis can be operationalized with the help of an agency-based supplier classification portfolio. It might be of particular value to firms to discuss those suppliers that scored high in risk of opportunism but did not (yet) reveal any signs of moral hazard. Finally, the strong explanatory power

of reputation alerts buyers to pay more attention to behavioral information on the (potential) supplier available in the market.

Originality/value: Analyzing the occurrence of moral hazard and including terminated relationships adds to the emerging stream of literature on relationship discontinuation in B2B markets. Further, the strong empirical results may encourage researchers to elaborate on principal-agent theory-based assumptions, adding another layer of explanation to buyer–supplier relationships. Findings show that reputation is unduly neglected as supplier selection criterion in current theory and practice.     

Buyer power in international markets

This paper investigates the implications for international markets of the existence of retailers/wholesalers with market power. Two main results are shown. First, in the presence of buyer power trade liberalization may lead to retail market concentration. Due to this concentration retail prices may be higher and welfare may be lower in free trade than in autarky, thus reversing the standard effects of trade liberalization. Second, the pro-competitive effects of trade liberalization are weaker under buyer power than under seller power.     

Exclusive dealing and common agency in international markets

This paper investigates the contractual choice between exclusive dealing and common agency in a simple international oligopoly model where products are sold through intermediaries. We find that when trade barriers are high, domestic firms tend to adopt exclusive dealing contracts whereas trade liberalization may lead firms to choose common agency. Social welfare can be raised be prohibiting exclusive dealing (common agency) when trade barriers are high (low) and products are close substitutes.     

Europe – Quo Vadis? Reflections on the Future Institutional Framework of the European Union

With twelve new members the decision making in the European Union via intergovernmental cooperation will become ineffective. The EU is at the Cross Roads. In order to avoid a Stagno‐Europe the EU has a choice: Either it looks for the very essentials in the common institutional framework and adjusts it accordingly or the member states agree in ceding national sovereignty to the European level. This, however, requires that the democratic deficit at the EU level is reduced. The Treaty of Nice has failed to solve these issues. The paper elaborates in detail the non‐essentials and the essentials of European integration and discusses the basics of an approach to a constitution‐like arrangement for Europe.     

Warentest mit der Funktionsanalyse

Zusammenfassung Das Ziel des Warentests läßt sich auf eine Entscheidungshilfe für den Kaufentschluß verdichten und durch Anwendung der vom Institut für Produktforschung und Information entwickelten Funktionsanalyse verwirklichen. Das zugrundegelegte Entscheidungsmodell enthält die Elemente: Verwendungszweck, Angebot von Waren für denselben Verwendungszweck (= Arbeitsmittel), Prozeß der Entscheidungsvorbereitung. Der Verwendungszweck kann im Nutzungssystem »Mesch-Arbeitsmittel-Umwelt« beschrieben werden. Er führt zu einer hierarchisch gegliederten Nennfunktion, deren Unterfunktionen die Beiträge aller Basisbeziehungen im Nutzungssystem zur Zweckerfüllung erfassen. Die nutzungsorientierten Anforderungen präzisieren als Gewichtungsprogramm das Funktionssystem. Anhand von objektiven Beurteilungsmaßstäben werden den Tauglichkeitsmerkmalen der Arbeitsmittel Ist-Tauglichkeiten als Werturteile zugeordnet. Die Gesamt-Gebrauchstauglichkeit — als Eignungsmaß — wird aus den Teilurteilen errechnet. Beispiele zeigen die Vorteile der Funktionsanalyse im Vergleich zum Vorgehen der Stiftung Warentest.

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Comparative testing of products by analysing product functions

The methodology described has been developed in Institut für Produktforschung und Information (ipi), Stuttgart. It is based on a decision-process model, consisting of the elements: purpose of use, set of products intended for the purpose, and data processing system. Purpose of use can be described with the help of an ergonomic system containing three elements: man (= user), tool, and environment. With further sub-divisions, this leads to a hierarchical system, the sub-functions of which enclose all relationships in the given system. Differing requirements concerning the sub-functions, for different uses of the product, are adapted to by a set of weighting factors. The value-for-use (performance) of a product's characteristics is measured on a 10 point value-scale. In most cases, it is possible to calculate the overall result as the weighted arithmetic mean of all sub-functions. This analysis of product functions realizes all principles of comparative testing such as they are given, for instance, in the German standards DIN 66050 and DIN 66052. There are also advantages compared with the methodology used by Stiftung Warentest.

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Horst Dürr ist geschäftsführender Gesellschafter des Instituts für Produktforschung und Information GmbH, Arlbergstraße 9, D-7000 Stuttgart 60.     

Processing mineral raw materials

Processing of raw materials by the producer countries themselves has frequently been recommended as an appropriate way for developing countries to increase their domestic value added and achieve positive employment effects. As against that, the following article suggests that Third World governments should not take hasty investment decisions in favour of processing raw materials since the effects on the national economy in terms of the cost-benefit ratio could well be more favourable in other branches of industry.     

The effect of the human pheromone androstenol on product evaluation

The chemical communication between humans has received considerable attention recently. Among the findings in psychology and anthropology have been the effects of putative human pheromones on the evaluation of persons. This article investigates if the finding that the pheromone androstenol influences person evaluation extends to the evaluation of products. In a laboratory experiment, 120 participants randomly assigned to either an experimental or control group rated three magazines. It was found that male consumers evaluate male magazines as more masculine and more positively under the influence of the putative male pheromone androstenol, whereas no such effects were found for magazines rated neutral or feminine and with respect to female consumers. Possible contextual and other factors influencing these results are discussed. © 2005 Wiley Periodicals, Inc.     

Konjunkturschlaglicht: Leicht höhere Steuereinnahmen

HWWA-KONJUNKTURFORUM

Konjunkturschlaglicht: Leicht h?here Steuereinnahmen     

Employment stability in newly founded firms: a matching approach using linked employer–employee data from Germany

Using a linked employer–employee dataset and taking the perspective of individuals rather than firms, this paper analyzes some effects of joining startups. We show that entrants in new firms differ from those joining incumbent firms, and we use a matching approach to compare a group of employees joining new firms in 1995/1996 with a control group entering incumbent firms. Our results indicate that individuals’ employment stability was higher in incumbent than in newly founded firms, while their risk of becoming unemployed was lower. In particular in eastern Germany, joining firms that were older than 6 years improved individuals’ employment prospects.