Prediction Markets: Prognosemärkte in Praxis und Theorie - Ein Überblick
Marian Berneburg
External Publications,
2008
Abstract
A common joke among economist is: Why has god created meteorologists? To make the forecasts of economist look less bad! At the heart of this joke stands the critique that economic forecasts are notoriously inaccurate. Prediction Markets are an attempt to improve these forecasts by aggregating the knowledge of many. The present article takes a closer look at these Prediction Markets. By analysing the existing literature in terms of the relevant theoretical as well as empirical basis, it is shown that an adapted version of the model by Kyle (1985) with noise and insider traders is able to explain the high degree of predictive accuracy, i. e. informational efficiency, of prediction markets. At the same time such a model is able to cope with the Grossman-Stiglitz Paradox (1976) or the No-Trade Theorem (Milgrom & Stokey, 1982), both are common theoretical arguments against informational efficiency. This allows the interpretation of market prices as event probabilities. Even though some empirical artefacts (e. g. the favorite-longshot bias) exist and more research, especially in terms of prediction markets covering economic events, is needed, the overall verdict on these forecasting tools has to be that they are roughly semi-strong efficient. They hence provide an interesting, very accurate and additional tool in forecasting.
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Institutions and Clusters
Ulrich Blum
Handbook on Research on Clusters,
2009
Abstract
We show that transaction costs and external economies, which change institutional arrangements heavily, influence cluster structures. Two types of clusters, (i) the vertical cluster where a hub dominates suppliers that have settled in the vicinity and, (ii), the horizontal cluster where firms share a common platform – historically a natural resource, today often knowledge and competences. Furthermore, non-cluster firms exist. We show, in a model, how these types emerge from the interaction found in firms and the interaction of firms within a network system. Changing transaction costs and externalities influence clusters and produce cluster dynamics. The sustainability of a cluster depends on its ability to stabilize the basis of its existence. This is easier for horizontal clusters that can steadily develop their knowledge and competence platform than for a vertical cluster which heavily depends on product life cycles. We give some evidence for clusters in East Germany, which presents an interesting example. The Treuhand atomized the giant combines, so that the rearrangements may be interpreted as results of fundamental market forces. Therefore major influences on the emerging institutional structure should stem from transaction costs and externalities.
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Evaluating communication strategies for public agencies: transparency, opacity, and secrecy
Axel Lindner
IWH Discussion Papers,
No. 8,
2008
Abstract
This paper analyses in a simple global games framework welfare effects stemming
from different communication strategies of public agencies if strategies of agents are complementary to each other: communication can either be fully transparent, or the agency opaquely publishes only its overall assessment of the economy, or it keeps information completely secret. It is shown that private agents put more weight to their private information in the transparent case than in case of opacity. Thus, in many cases, the appropriate measure against overreliance on public information is giving more details to the public instead of denying access to public information.
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Does too much Transparency of Central Banks Prevent Agents from Using their Private Information Efficiently?
Axel Lindner
IWH Discussion Papers,
No. 16,
2007
Abstract
This paper analyses in a simple global games framework welfare effects of different communication strategies of a central bank: it can either publish no more than its overall assessment of the economy or be more transparent, giving detailed reasons for this assessment. The latter strategy is shown to be superior because it enables agents to use private information and to be less dependent on common knowledge. This result holds true even if the strategies of agents are strategic complements, for which case it has been argued that too much transparency might induce agents to neglect their private knowledge.
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Threshold for employment and unemployment. A spatial analysis of German RLM's 1992-2000
Christian Dreger, Reinhold Kosfeld
External Publications,
2006
Abstract
Changes in production and employment are closely related over the course of the business cycle. However, as exemplified by the laws of Verdoorn (1949, 1993) and Okun (1962, 1970), thresholds seem to be present in the relationship. Due to capacity reserves of the firms, output growth must exceed certain levels for the creation of new jobs or a fall in the unemployment rate. While Verdoorn's law focuses on the growth rate of output sufficient for an increase in employment, in Okun's law, the fall in the unemployment rate becomes the focus of attention. In order to assess the future development of employment and unemployment, these thresholds have to be taken into account. They serve as important guidelines for policymakers. In contrast to previous studies, we present joint estimates for both the employment and unemployment threshold. Due to demographic patterns and institutional settings on the labour market, the two thresholds can differ, implying that minimum output growth needed for a rise in employment may not be sufficient for a simultaneous drop in the unemployment rate. Second, regional information is considered to a large extent. In particular, the analysis is carried out using a sample of 180 German regional labour markets, see Eckey (2001). Since the cross-sections are separated by the flows of job commuters, they correspond to travel-to-work areas. Labour mobility is high within a market, but low among the entities. As the sectoral decomposition of economic activities varies across the regions, the thresholds are founded on a heterogeneous experience, leading to more reliable estimates.The contribution to the literature is twofold. First, to the best of our knowledge, no previous paper has investigated a similar broad regional dataset for the German economy as a whole before. By using a panel dataset, information on the regional distributions around the regression lines as well as theirs positional changes is provided for each year. Second, the methods applied are of new type. They involve a mixture of pooled and spatial econometric techniques. Dependencies across the regions may result from common or idiosyncratic (region specific) shocks. In particular, the eigenfunction decomposition approach suggested by Griffith (1996, 2000) is used to identify spatial and non-spatial components in regression analysis. As the spatial pattern may vary over time, inference is conducted on the base of a spatial SUR model. Due to this setting, efficient estimates of the thresholds are obtained. With the aid of a geographic information system (GIS) variation of the spatial components can be made transparent. With Verdoorn’s and Okun’s law the figures show some significant patterns become obvious over time. In respect to Verdoorn’s law, for instance, a stripe of high values in the north-western part from Schleswig-Holstein via Lower Saxony and North Rhine Westfalia to Rhineland Palatinate is striking in all years but 1994 and 1995. In most periods the spatial component is likewise concentrated in Saxony. Clusters of low values can be found in northern Bavaria and, in some periods, in Thüringen and Mecklenburg-Vorpommern. Other parts of Germany appear to be more fragmented consisting of relative small clusters of low, medium and high values of the spatial component. With Okun’s law some changing spatial patterns arise. In all, spatially filtering provides valuable insights into the spatial dimensions of the laws of Verdoorn and Okun.
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Does Transparency of Central Banks produce Multiple Equilibria on Currency Markets?
Axel Lindner
Scandinavian Journal of Economics,
No. 1,
2006
Abstract
A recent strand of literature shows that multiple equilibria in models of markets for pegged currencies vanish if there is slightly diverse information among traders; see Morris and Shin (2001). It is known that this approach works only if the common knowledge in the market is not too precise. This has led to the conclusion that central banks should try to avoid making their information common knowledge. We develop a model in which more transparency of the central bank implies better private information, because each trader utilises public information according to her own private information. Thus, transparency makes multiple equilibria less likely.
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Does Transparency of Central Banks Produce Multiple Equilibria on Currency Markets?
Axel Lindner
IWH Discussion Papers,
No. 178,
2003
Abstract
A recent strand of literature (see Morris and Shin 2001) shows that multiple equilibria in models of markets for pegged currencies vanish if there is slightly diverse information between traders. It is known that this approach works only if there is not too precise common knowledge in the market. This has led to the conclusion that central banks should try to avoid making their information common knowledge. We present a model in which more transparency of the central bank means better private information, because each trader utilizes public information according to her own private information. Thus, transparency makes multiple equilibria less likely.
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