Judgment aggregation in search for the truth

We analyze the problem of aggregating judgments over multiple issues from the perspective of whether aggregate judgments manage to efficiently use all voters' private information. While new in judgment aggregation theory, this perspective is familiar in a different body of literature about voting between two alternatives where voters' disagreements stem from conflicts of information rather than of interest. Combining the two bodies of literature, we consider a simple judgment aggregation problem and model the private information underlying voters' judgments. Assuming that voters share a preference for true collective judgments, we analyze the resulting strategic incentives and determine which voting rules efficiently use all private information. We find that in certain, but not all cases a quota rule should be used, which decides on each issue according to whether the proportion of ‘yes’ votes exceeds a particular quota

Contractions of Lie algebras and algebraic groups

Degenerations, contractions and deformations of various algebraic structures play an important role in mathematics and physics. There are many different definitions and special cases of these notions. We try to give a general definition which unifies these notions and shows the connections among them. Here we focus on contractions of Lie algebras and algebraic groups

Using simple neural networks to analyse firm activity

Characteristically, in economics, the analysis of firm activity is based on a production function that defines a deterministic relationship between factor inputs and firm output. The analysis of the firm as an organisation takes a somewhat different approach. For instance, behavioural economics (for example Simon, 1955; March and Simon, 1958; Cyert and March, 1963), transaction cost theory (Williamson, 1975, 1985) and capabilities approaches (for example Foss and Loasby, 1998; Foss, 2005) emphasise that economic agents have inevitably incomplete information and knowledge and are at most boundedly or limitedly rational. The implication here is that while general principles governing intra-firm interaction can be specified, detailed organisational processes inside the firm are, for practical academic purposes, effectively unobservable. Hence, the usual analytical tools designed to analyse firm behaviour, based on production functions and optimising principles with full information, are in practice an oversimplification of firm activity (Loasby, 1999)

Modelling change in individual characteristics: an axiomatic framework

Economic models describe individuals in terms of underlying characteristics, such as taste for some good, sympathy level for another player, time discount rate, risk attitude, and so on. In real life, such characteristics change through experiences: taste for Mozart changes through listening to it, sympathy for another player through observing his moves, and so on. Models typically ignore change, not just for simplicity but also because it is unclear how to incorporate change. I introduce a general axiomatic framework for defining, analysing and comparing rival models of change. I show that seemingly basic postulates on modelling change together have strong implications, like irrelevance of the order in which someone has his experiences and ‘linearity’ of change. This is a step towards placing the modelling of change on solid axiomatic grounds and enabling non-arbitrary incorporation of change into economic models

Microfluidic free-flow electrophoresis for proteomics-on-a-chip

A new free-flow electrophoresis microchip with integrated permeable membranes was developed, and different substances were separated by free-flow zone electrophoresis, free-flow isoelectric focusing and free-flow field step electrophoresis. This chip contained a new type of membranes enabling a stable carrier flow with a perpendicular electrical current. Due to this chip configuration, the device performance and efficiency were superior to recenty published alternative systems in terms of separation resolution and sample capacity. The results furthermore indicate that even better results are possible. Analytes were separated and focused within hundreds of milliseconds whereby only nanoliters of samples were consumed. In addition, a new sample steering method was demonstrated during free-flow zone electrophoresis, allowing the specific sorting of various components. As an alternative, a free-flow electrophoresis chip was developed with integated platinum electrodes, whereby the generation of gas bubbles caused by electrolysis was successfully suppressed by chemical means. Gas bubbles generated by electrolysis are major concern in free-flow electrophoresis systems in general leading to distorted separation. Based on the results, a fourth free-flow chip was developed with an integrated surface plasmon resonance gold detection region. Although fabrication was successful, certain hurdles, in particular surface chemistry issues still remain to be overcome to perform separation and real-time detection of biological samples within this hyphenated micro device. A strategy for proteomics-on-a-chip was developed aiming at the separation of antigens that play a role in autoimmune diseases. In addition two new continuous flow microfluidic chips were developed allowing for continuous biochemical reactions of surface patterning applications. These devices could be of further interest in future, in particular in more complex analytical systems related to proteomics-on-a-chip

Transaction Costs and Profitability in UK Manufacturing

This paper explores the impact of transaction costs on performance at firm and industry levels using a sample of 7350 UK manufacturing firms. This is achieved by estimating a profit function with estimated transaction costs as a right hand side variable. The discussion has two specific objectives. (1) To show how firm and average industry transaction costs can be estimated using a stochastic frontier method. (2) To examine a central claim of transaction cost theory that links these costs to performance. In addition the different impacts of static and dynamic transaction costs are emphasised, with the different impacts being respectively negative and positive on profitability. Broadly speaking it is shown that such costs do impact on performance in a way consistent with both static and dynamic costs, in different industries, and that the impacts hold after a series of robustness checks. In addition it is shown that the impacts can depend on monopoly power, firm scale, and firm growth