Rationalizable implementation

We consider the implementation of social choice functions under complete information in rationalizable strategies. A strict version of the monotonicity condition introduced by Maskin is necessary under the solution concept of rationalizability. Assuming the social choice function is responsive, i.e. in distinct states it selects distinct outcomes, we show that strict Maskin monotonicity is also sufficient under a mild “no worst alternative” condition. In particular, no economic condition is required. We discuss how our results extend when the social choice function is not responsive.     

Value creation,competition, and performance in buyer‐supplier relationships

The value‐based approach to strategy argues that a firm's ability to capture value depends on the extent of its added value. In this paper, I empirically test the link between added value and value capture using a longitudinal dataset of United Kingdom law firm performance, capabilities, and client relationships. In this setting, competitors relevant for defining a firm's added value are those that share a client with the firm. Further, within a client relationship, value creation, and hence added value, can be decomposed in two parts: product‐line capability and client‐specific scope economies. I find that added value, measured at the level of each buyer‐supplier relationship, is a driver of relationship stability and supplier profitability. This suggests that suppliers with similar capabilities might enjoy different economic returns depending on the composition of their set of relevant competitors. These findings shed light on the conditions under which firms can appropriate returns from their capabilities. They indicate that concepts from cooperative games can be fruitfully applied to empirical studies of firm performance and to the elaboration of insights from the resource‐based view of the firm. Copyright © 2010 John Wiley & Sons, Ltd.     

Back to the basics in banking? A micro-analysis of banking system stability

This paper analyzes the relationship between banks’ divergent strategies toward specialization and diversification of financial activities and their ability to withstand a banking sector crash. We first generate market-based measures of banks’ systemic risk exposures using extreme value analysis. Systemic banking risk is measured as the tail beta, which equals the probability of a sharp decline in a bank’s stock price conditional on a crash in a banking index. Subsequently, the impact of (the correlation between) interest income and the components of non-interest income on this risk measure is assessed. The heterogeneity in extreme bank risk is attributed to differences in the scope of non-traditional banking activities: non-interest generating activities increase banks’ tail beta. In addition, smaller banks and better-capitalized banks are better able to withstand extremely adverse conditions. These relationships are stronger during turbulent times compared to normal economic conditions. Overall, diversifying financial activities under one umbrella institution does not improve banking system stability, which may explain why financial conglomerates trade at a discount.     

Interest rate expectations and uncertainty during ECB Governing Council days: Evidence from intraday implied densities of 3-month EURIBOR

This paper analyses changes in short-term interest rate expectations and uncertainty during ECB Governing Council days. For this purpose, it extends the estimation of risk-neutral probability density functions up to tick frequency. In particular, the non-parametric estimator of these densities, which is based on fitting implied volatility curves, is applied to estimate intraday expectations of 3-month EURIBOR 3 months ahead. Estimates of the noise impact on the statistical moments of the densities enhance the interpretation. In addition, the paper assesses the impact of the ECB communication during Governing Council days. The results show that the whole density may react to the communication and that such repositioning of market participants’ expectations will contain information beyond that of changes in the consensus view already observed in forward rates. The results also point out the relevance of the press conference in providing extra information and triggering an adjustment process for interest rate expectations.     

International bailouts, moral hazard and conditionality

The large international bailouts of the 1990s have been criticized for generating moral hazard at the expense of the global taxpayer. We argue that this criticism is misleading because international bailouts create no, or very few, costs to the international community. Instead, the problem is to ensure that bailouts are not used to facilitate bad domestic policies, thus creating moral hazard at the expense of domestic taxpayers. This may require a shift towards ex ante conditionality, in the sense that the availability and size of official crisis lending need to be conditional on government policies before the crisis.     

Folksonomies: Spontaneous crowd sourcing with online early detection potential?

This article focuses on the analysis of this distributed, heterogeneous, open and continuous production of “data about data” and its possible contribution to early detection objectives. It assesses whether the related processes of open classification and free annotation could provide promising results not only for information retrieval goals, which they are meant for, but also for detecting weak signals of incoming changes.     

A Mathematical Programming Approach for Measuring Technical Efficiency in a Fuzzy Environment

A three stage approach is proposed to measure technical efficiency in a fuzzy environment. This approach uses the traditional data envelopment analysis framework and then merges concepts developed in fuzzy parametric programming (Carlsson and Korhonen, 1986). In the first stage, vague input and output variables are expressed in terms of their risk-free and impossible bounds and a membership function. This membership function represents the degree to which a production scenario is plausible. In the second stage, conventional efficiency measurement models (Banker, Charnes and Cooper, 1984; Deprins, Simar and Tulkens, 1984) are re-formulated in terms of the risk-free and impossible bounds and the membership function for each of the fuzzy input and output variables. In the third stage, technical efficiency scores are computed for different values of the membership function so as to identify uniquely sensitive decision making units. The approach is illustrated in the context of a preprint and packaging manufacturing line which inserts commercial pamphlets into newspapers.     

Building a 3-D model of a flood basalt: an example from the Etendeka, NW Namibia

Flood basalts represent large outpourings of lavas which often cover, and interact with, sedimentary basins. For this reason areas with significant flood basalt cover are often targets for hydrocarbon exploration. Problems exist, however, when trying to image sediments and structures in offshore regions covered by basalts. Here we present preliminary 3-D models of the Etendeka flood basalt province from NW Namibia, which can act as an aid in understanding the internal and external architecture of the flood basalt cover. Satellite images, digital elevation models, measured geological logs, sections and maps, are used to create the geological model. Models are presented in 2 parts; 1) models created using topography with images such as Land Sat and geological maps draped over them, and 2) a 3-D model of key lava and sediment surfaces in the basin as defined by measured geological sections. Initial results show a palaeo-volcanic feature early in the flood basalt history which is onlapped by later Iavas. The modelling also allows a simple correction for post emplacement subsidence by assuming an original sub horizontal position for the first basin wide silicic flow unit.     

On Sustaining Cooperation without Public Observations

This paper examines a dynamic game in which each player only observes a private and imperfect signal on the actions played. Our main result is that in a repeated prisoner's dilemma where defections are irreversible (at least for a long enough period of time), patient enough players may achieve almost efficient outcomes. Dealing with models of imperfect private monitoring is difficult because (i) continuation games are games of incomplete information, hence they do not have the same structure as the original game. In particular, continuation equilibria are correlated equilibria. (ii) Players are typically uncertain about their opponents' past observations and actions, and they use their entire own private history to learn about these actions. As a result equilibrium strategies are in general nontrivial and increasingly complex functions of past observations. We bypass these difficulties by looking at correlated equilibria of the original game and find correlated equilibria in which the decision problem faced by each player remains the same over time. Journal of Economic Literature Classification Numbers: C72.