A Markov model of Diabetic Retinopathy Progression for the Economic Evaluation of a novel DR prognostic device, CHERE Working Paper 2007/14

The initial diagnosis of Diabetic Retinopathy (DR) is often in the advance stages of the condition, as patients are only promoted for an examination when sight has been affected. An innovative prognostic technique has recently been made available which can non-invasively detect the damaging effects of high blood glucose before the development of clinical symptoms. This innovation offers the opportunity to patients to make the necessary behavioural and medicinal modification to prevent further progress of the disease. This paper reports the development of a Markov model which emulates the natural progression of Diabetic Retinopathy based on data from clinical trials. The purpose of such a model is to estimate the chronic cost and health outcomes of DR, and it may be modified to reflect the potential changes in current practice or condition changes, hence allowing for an economic evaluation of the DR prognostic test. The implications and limitations of the model were also discussed in the paper.Diabetic retinopathy, economic evaluation

Auction Fever: Theory and Experimental Evidence

It is not a secret that certain auction formats yield on average higher prices than others. The phenomenon that dynamic auctions are more likely to elicit higher bids than static one-shot auctions is often associated with the term ''auction fever.'' On a psychological level, we consider the so-called pseudo-endowment effect as largely responsible for peoples’ tendency to submit higher bids, potentially amplified by the source-dependence effect. The phenomenon of auction fever is replicated in an experimental investigation of different auction formats within a private values framework where bidders have private but incomplete knowledge of their valuation for a hypothetical good. We suggest this assumption to be more realistic than definite private values, as assumed in the traditional IPV model. An additional experimental investigation within the traditional IPV framework does not either reveal any indication for the appearance of auction fever. On the basis of our experimental observations we present a model of reference-dependent utility theory that comprehends the phenomenon by assuming that bidders' reference points are shifted by the pseudo-endowment and the source-dependence effect.

Myopically Forward-Looking Agents in a Network Formation Game: Theory and Experimental Evidence

A population of players is considered in which each agent can select her neighbors in order to play a 2x2 Hawk-Dove game with each of them. We design our experiment in continuous time where participants may change their Hawk-Dove action and/or their neighborhood at any point in time. We are interested in the resulting formation of networks and the action distributions. Compared with static Nash equilibrium (e.g., Berninghaus and Vogt, 2004, 2006; Bramoulle, Lopez-Pintado, Goyal, and Vega-Redondo, 2004) and social optimum as theoretical benchmark solutions, subjects seem to employ a more complex, forward-looking thinking. We develop an other benchmark solution, called one-step-ahead stability, that combines forward-looking belief formation with rational response and that fits the data much better.

Requirements for Electronic Commerce Protocols in Business-to-Business Markets

This paper describes the requirements for electronic commerce protocols in business-to-business markets. A protocol comprises rules for communication between com- munication partners. In the world of electronic commerce such protocols need to be designed for the support of auto- mated communication between information systems of different participants. We want to set a focus on protocols for negotiation processes in electronic procurement. These processes are not supported appropriately in traditional standard protocols like ANSI X.12. We outline the re- quirements for an open and extensible protocol that com- prises electronic negotiation on multiple attributes of a deal

Auctions, information, and new technologies

Auctions have been developed for economic transactions with asymmetric information and they are the simplest means of price determination for multilateral trading without "market makers." During the last years, new technologies gave a boost to the development and usage of innovative auction formats in several fields. We explore some of the new possibilities of applications and explain the differences to traditional auction formats. Furthermore, we demonstrate the potentialities of auctions concerning information gaining for the auctioneer as well as for the participating bidders

Evaluation Factors for Multi-Stakeholder Broadband Visual Communication Projects

This paper presents a summary of multifaceted evaluation factors that we have identified through our research with Broadband Visual Communication (BVC) projects involving multiple stakeholders. The main benefit of these evaluation factors is that they provide a general evaluation framework for multiple stakeholder projects. The factors are social infrastructure, technical infrastructure, physical space, interaction style and content

Poly-substance use and sexual risk behaviours: a cross-sectional comparison of adolescents in mainstream and alternative education settings

Background: Surveys of young people under-represent those in alternative education settings (AES), potentially disguising health inequalities. We present the first quantitative UK evidence of health inequalities between AES and mainstream education school (MES) pupils, assessing whether observed inequalities are attributable to socioeconomic, familial, educational and peer factors. Methods: Cross-sectional, self-reported data on individual- and poly-substance use (PSU: combined tobacco, alcohol and cannabis use) and sexual risk-taking from 219 pupils in AES (mean age 15.9 years) were compared with data from 4024 pupils in MES (mean age 15.5 years). Data were collected from 2008 to 2009 as part of the quasi-experimental evaluation of Healthy Respect 2 (HR2). Results: AES pupils reported higher levels of substance use, including tobacco use, weekly drunkenness, using cannabis at least once a week and engaging in PSU at least once a week. AES pupils also reported higher levels of sexual health risk behaviours than their MES counterparts, including: earlier sexual activity; less protection against sexually transmitted infections (STIs); and having 3+ lifetime sexual partners. In multivariate analyses, inequalities in sexual risk-taking were fully explained after adjusting for higher deprivation, lower parental monitoring, lower parent-child connectedness, school disengagement and heightened intentions towards early parenthood among AES vs MES pupils. However, an increased risk (OR = 1.73, 95% CI 1.15, 2.60) of weekly PSU was found for AES vs MES pupils after adjusting for these factors and the influence of peer behaviours. Conclusion: AES pupils are more likely to engage in health risk behaviours, including PSU and sexual risk-taking, compared with MES pupils. AES pupils are a vulnerable group who may not be easily targeted by conventional population-level public health programmes. Health promotion interventions need to be tailored and contextualised for AES pupils, in particular for sexual health and PSU. These could be included within interventions designed to promote broader outcomes such as mental wellbeing, educational engagement, raise future aspirations and promote resilience

Auctions, information, and new technologies

Auctions have been developed for economic transactions with asymmetric information and they are the simplest means of price determination for multilateral trading without "market makers." During the last years, new technologies gave a boost to the development and usage of innovative auction formats in several fields. We explore some of the new possibilities of applications and explain the differences to traditional auction formats. Furthermore, we demonstrate the potentialities of auctions concerning information gaining for the auctioneer as well as for the participating bidders

How the auction design influences procurement prices: an experiment

The targeted design of auctions has to take behavioral regularities into account. This paper explores whether procurement auction formats can take advantage of bidders' willingness-to-pay-willingness-to-accept disparity. In a laboratory experiment, we compare four different second-price auction formats for procuring a good. The four formats are a sealed-bid auction and three different descending-clock auctions. We assume that a bidder's willingness-to-accept exceeds his willingness-to-pay and that, depending on the auction format, a bidder's reference-state shifts such that the bidder's perspective moves from a willingness-to-accept perspective towards a willingness-to-pay perspective, thus inducing aggressive bids. In line with the prediction, auction prices decline across the four formats. In particular, we observe the lowest prices in those two clock auction formats that, at every auction stage, select a bidder as the current leading bidder. We conclude that mechanisms influence the reference state and that auctions that foster reference-state shifts lead to lower payments for the buyer. These results support and generalize findings on sales auctions. However, not all of our findings on procurement auctions mirror findings on sales auctions. Bidders overbid in sealed-bid procurement auctions, which does not mirror the commonly observed overbidding in sealed-bid sales auctions