Association of financial or professional conflict of interest to research outcomes on health risks or nutritional assessment studies of genetically modified products

Since the first commercial cultivation of genetically modified crops in 1994, the rapidly expanding market of genetically modified seeds has given rise to a multibillion dollar industry. This fast growth, fueled by high expectations towards this new commercial technology and shareholder trust in the involved industry, has provided strong incentives for further research and development of new genetically modified plant varieties. Considering, however, the high financial stakes involved, concerns are raised over the influence that conflicts of interest may place upon articles published in peer-reviewed journals that report on health risks or nutritional value of genetically modified food products. In a study involving 94 articles selected through objective criteria, it was found that the existence of either financial or professional conflict of interest was associated to study outcomes that cast genetically modified products in a favorable light (p = 0.005). While financial conflict of interest alone did not correlate with research results (p = 0.631), a strong association was found between author affiliation to industry (professional conflict of interest) and study outcome (p < 0.001). We discuss these results by comparing them to similar studies on conflicts of interest in other areas, such as biomedical sciences, and hypothesize on dynamics that may help explain such connections.     

Fluctuating Efforts and Interdependencies in Collaborative Work

We present a dynamical model of cooperative efforts comprised of concurrently performed, interrelated tasks. The model contains a stochastic component to account for temporal fluctuations both in task performance and in the effect of a given unit of work on the project as a whole. We show that as the number of concurrent tasks increases, so does the average completion time. Also, for fixed system size, the dynamics of individual project realizations can exhibit large deviations from the average when fluctuations increase past a certain threshold, causing long delays in completion times. These effects are in agreement with empirical observation. We also show that the negative effects of both large groups and long delays caused by fluctuations may be mitigated by arranging projects in a hierarchical or modular structure. Our model is applicable to any arrangement of interdependent tasks, providing an analytical prediction for the average completion time as well as a numerical threshold for the fluctuation strength beyond which long delays are likely. In conjunction with previous modeling techniques, it thus provides managers with a predictive tool to be used in the design of a project’s architecture.     

Dynamic coordination with timing frictions: Theory and applications

We present a general framework of dynamic coordination with timing frictions. A continuum of agents receive random chances to choose between two actions and remain locked in the selected action until their next opportunity to reoptimize. The instantaneous utility from each action depends on an exogenous fundamental that moves stochastically and on the mass of agents currently playing each action. Agents' decisions are strategic complements and history matters. We review some key theoretical results and show a general method to solve the social planner's problem. We then review applications of this framework to different economic problems: network externalities, statistical discrimination, and business cycles. The positive implications of these models are very similar, but the social planner's solution points to very different results for efficiency in each case. Last, we review extensions of the framework that allow for endogenous hazard rates and ex ante heterogeneous agents.     

Modelling non-performing loans probability in the commercial banking system: efficiency and effectiveness related to credit risk in Italy

In this article, we model the effect of the non-performing loans on the cost structure of the commercial banking system. With this aim, we comment on an increase in the non-performing loans by studying the consequences of such a change on the cost function and compute the probability of failure of maintaining a performing loan as such. In doing so, we are convinced that geography does matter and evaluate the risk propensity of the bank towards the non-performing loans accordingly. We finally stress that traditional efficiency indicators of cost elasticity do not fit properly with such a problem and propose a measure based on the costs for managing and monitoring the loans which, according to the related density function, will reveal effectively as non performing.     

Participation in Workplace Pension Schemes and the Effect of Provision: Evidence from the United Kingdom*

This study investigates the effect of public policies enforcing workplace pension plan provision on participation rates. Using British data covering almost two decades (1992–2009), I identify the potential opt‐in rate among private sector workers who have not been offered a workplace pension plan, had they been offered the opportunity to join such a saving scheme. I find that universal provision of workplace pension schemes alone could generate a major impact on pension coverage.     

Costly contracting in a long‐term relationship

We examine a model of contracting where parties interact repeatedly and can contract at any point in time, but writing formal contracts is costly. A contract can describe the external environment and the parties' behavior in a more or less detailed way, and the cost of writing a contract is proportional to the amount of detail. We consider both formal (externally enforced) and informal (self‐enforcing) contracts. The presence of writing costs has important implications both for the optimal structure of formal contracts, particularly the tradeoff between contingent and spot contracting, and for the interaction between formal and informal contracting. Our model sheds light on these implications and generates a rich set of predictions about the determinants of the optimal mode of contracting.     

A Theory of Dividends Based on Tax Clienteles

This paper explains why some firms prefer to pay dividends rather than repurchase shares. When institutional investors are relatively less taxed than individual investors, dividends induce "ownership clientele" effects. Firms paying dividends attract relatively more institutions, which have a relative advantage in detecting high firm quality and in ensuring firms are well managed. The theory is consistent with some documented regularities, specifically both the presence and stickiness of dividends, and offers novel empirical implications, e.g., a prediction that it is the tax difference between institutions and retail investors that determines dividend payments, not the absolute tax payments.     

A Statistical Approach to Assess Referendum Results: the Venezuelan Recall Referendum 2004

This article presents a statistical approach to assess the coherence of official results of referendum processes. The statistical analysis described is divided in four phases, according to the methodology used and the corresponding results: (1) Initial Study, (2) Quantification of irregular certificates of election, (3) Identification of irregular voting centers and (4) Estimation of recall referendum results.
The technique of cluster analysis is applied to address the issue of heterogeneity of the parishes with respect to their political preferences.
The Venezuelan recall referendum 2004 is the case study we used to apply the proposed methodology, based on the data published by the "Consejo Nacional Electoral" (CNE-National Electoral Council). Finally, we present the conclusions of the study which we summarize as follows: The percentage of irregular certificates of election is between 22.2% and 26.5% of the total; 18% of the voting centers show an irregular voting pattern in their certificates of election, the votes corresponding to this irregularity are around 2,550,000; The result estimate, using the unbiased votes as representative of the population for the percentage of YES votes against President Chávez is 56.4% as opposed to the official result of 41%.