Informational opacity and honest certification

This paper studies the interaction of information disclosure and reputational concerns in certification markets. We argue that by revealing less precise information a certifier reduces the threat of capture. Opaque disclosure rules may reduce profits but also constrain feasible bribes. For large discount factors a certifier is unconstrained in the choice of a disclosure rule and full disclosure maximizes profits. For intermediate discount factors, only less precise, such as noisy, disclosure rules are implementable. Our results suggest that contrary to the common view, coarse disclosure may be socially desirable. A ban may provoke market failure especially in industries where certifier reputational rents are low

Drei Essays über Kommunikation in Signalspielen

Diese Dissertation befasst sich mit verschiedenen ökonomischen Anwendungen von Signalspielen. In dieser Art von Spielen übermittelt ein Sender einem Empfänger Information, die dieser interpretiert. Bildungsinstitutionen - Sender - bewerten Studenten nach einem festgelegten Notensystem. Die vollständige Offenlegung von Information ist die beste Strategie von Institutionen, wenn Studenten ihren erwarteten Nutzen maximieren. Untersucht wird eine Abweichung hiervon: menschliche Wahrnehmung konzentriert sich oftmals auf besonders auffällige Zustände - hier sehr gute oder sehr schlechte Noten. Es wird gezeigt, wie dieses Verhalten Bildungsinstitutionen dazu bringt, Notensysteme gröber zu gestalten. Während davon ausgegangen werden kann, dass Bildungsinstitutionen Informationen, wenn schon nicht vollständig, so doch wahrheitsgemäß offenlegen, ist dies bei privatwirtschaftlich organisierten Zertifizierern nicht notwendigerweise der Fall. Ist die Manipulation von Information nicht möglich, sollte ein Zertifizierer Interesse an der vollständigen Offenlegung von Informationen haben, wenn Produzenten Einfluss auf die Qualität ihrer Güter nehmen. Hier wird gezeigt, dass, besteht die Möglichkeit zur Falschzertifizierung, dies nicht mehr der Fall ist. Eine reduzierte Transparenz ist nicht nur im Sinne des Zeritifizierers wünschenswert, sondern sichert auch die Funktionsfähigkeit von Märkten. In dem Markt für Lebensversicherungen können Firmen, welche asymmetrisch über das Risiko von Bewerbern informiert sind, von diesem Zustand profitieren. Information wird implizit über Vertragsangebote an Bewerber und Wettbewerber übermittelt. Es wird gezeigt, wie durch die Tatsache, dass eine informierte Firma nicht in der Lage ist, Information überzeugend zu übermitteln, Industriegewinne zulasten der Konsumenten gesteigert werden können. Diese Marktstruktur wird geschaffen durch den Austausch von Informationen über das Verhandlungsverhalten der Bewerber.This dissertation is concerned with various economic applications of signalling games. In this type of games, a sender transmits information to a receiver, who interprets it. Educational institutions - senders - evaluate students based on a fixed grading scale. Full disclosure of information is the best response by schools to a student body that consists of expected utility maximizers. The impact of a deviation from this behaviour is investigated: the human mind typically focuses on salient states - the very best or worst grades here. It is demonstrated how this behaviour brings educational institutions to employ coarse, rather than fine, grading schemes. While educational institutions presumably disclose information truthfully, this is not necessarily the case for privately organized certifiers. If information manipulation is not possible, a certifier should be interested in fully revealing information; at least if producer investment correlates with product quality. It is shown that if this so called threat of capture exists, information disclosure may be coarse. A reduced transparency may also increase social welfare because it prevents the market from breaking down. In the market for life insurances, firms which are asymmetrically informed about the risk of applicants, might benefit hereof. Information is implicitly transmitted to applicants and competitors via contract offers. It is shown how the non-ability of an informed firm to persuasively transmit information serves all insurers. Industry profits increase at the expense of consumers. This structure is created by the exchange of information on the bargaining behaviour of applicants

Transcriptional Activation of the tad Type IVb Pilus Operon by PypB in Yersinia enterocolitica▿

Type IV pili are virulence factors in various bacteria and mediate, among other functions, the colonization of diverse surfaces. Various subclasses of type IV pili have been identified, but information on pilus expression, biogenesis, and the associated phenotypes is sparse for the genus Yersinia. We recently described the identification of PypB as a transcriptional regulator in Yersinia enterocolitica. Here we show that the pypB gene is associated with the tad locus, a genomic island that is widespread among bacterial and archaeal species. The genetic linkage of pypB with the tad locus is conserved throughout the yersiniae but is not found among other bacteria carrying the tad locus. We show that the genes of the tad locus form an operon in Y. enterocolitica that is controlled by PypB and that pypB is part of this operon. The tad genes encode functions necessary for the biogenesis of the Flp subfamily of type IVb pili initially described for Aggregatibacter actinomycetemcomitans to mediate a tight-adherence phenotype. In Y. enterocolitica, the Flp pilin protein shows some peculiarities in its amino acid sequence that imply similarities as well as differences compared to typical motifs found in the Flp subtype of type IVb pili. Flp is expressed and processed after PypB overproduction, resulting in microcolony formation but not in increased adherence to biotic or abiotic surfaces. Our data describe the transcriptional regulation of the tad type IVb pilus operon by PypB in Y. enterocolitica but fail to show most previously described phenotypes associated with this type of pilus in other bacteria